6-K

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

Form 6-K

REPORT OF FOREIGN PRIVATE ISSUER

PURSUANT TO RULE 13a-16 OR 15d-16 UNDER
THE SECURITIES EXCHANGE ACT OF 1934

For the month of May 2018
Commission File Number: 001-36898

COLLIERS INTERNATIONAL GROUP INC.
(Translation of registrant's name into English)

1140 Bay Street, Suite 4000
Toronto, Ontario, Canada
M5S 2B4
(Address of principal executive office)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.
Form 20-F [   ]      Form 40-F [ X ]

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1): [   ]

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7): [   ]

Indicate by check mark whether by furnishing the information contained in this Form, the Registrant is also thereby furnishing the information to the Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934:

Yes [  ]                                                    No [X]

If “Yes” is marked, indicate the file number assigned to the Registrant in connection with Rule 12g3-2(b):  N/A

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

	COLLIERS INTERNATIONAL GROUP INC.
Date: May 1, 2018	/s/ John B. Friedrichsen
	Name: John B. Friedrichsen
	Title: Chief Financial Officer

EXHIBIT INDEX

Exhibit	Description of Exhibit
99.1	Press release dated May 1, 2018 announcing financial results for the first quarter ended March 31, 2018.
99.2	Supplemental slide presentation dated May 1, 2018.

EX-99.1

EXHIBIT 99.1

Colliers International Reports First Quarter Results

Strong growth in revenues and earnings

Operating highlights:

	Three months ended
	March 31
(in millions of US$, except EPS)	2018		2017
Revenues	$	552.5	$	466.3
Adjusted EBITDA (note 1)		36.1		31.3
Adjusted EPS (note 2)		0.45		0.36
GAAP operating earnings		15.7		12.8
GAAP EPS		0.13		0.04

TORONTO, May 01, 2018 (GLOBE NEWSWIRE) -- Colliers International Group Inc. (NASDAQ:CIGI) (TSX:CIGI) today reported operating and financial results for its first quarter ended March 31, 2018. All amounts are in US dollars.

Revenues for the first quarter were $552.5 million, an 18% increase (14% in local currency) relative to the same quarter in the prior year, Adjusted EBITDA (note 1) was $36.1 million, up 16% (14% in local currency) and Adjusted EPS (note 2) was $0.45, a 25% increase versus the prior year quarter. First quarter adjusted EPS would have been approximately $0.01 lower excluding foreign exchange impacts. GAAP operating earnings were $15.7 million, relative to $12.8 million reported in the prior year period. GAAP diluted net earnings per common share was $0.13 for the quarter, versus $0.04 per share for the same quarter a year ago. First quarter GAAP EPS would have been approximately $0.01 lower excluding foreign exchange impacts. Operating results for the first quarter of 2018 reflect the adoption of new US GAAP revenue guidance which became effective January 1, 2018. The comparative quarter has been restated to reflect the impact of the new revenue guidance.

“Colliers is off to a strong start in 2018, with well-balanced revenue growth from acquisitions and internally from our existing operations. Our revenue pipelines indicate solid activity across all service lines, with stable to positive conditions in most major markets,” said Jay S. Hennick, Chairman and CEO of Colliers International. “To date we have completed a total of five acquisitions, two in the Americas, two in Europe and one in Asia - investing more than $100 million. Last month we also completed the expansion and extension of our revolving credit facility, providing additional capacity for growth over the next five years. With our strong balance sheet, disciplined growth strategy, and proven track record, Colliers International is well positioned to continue expanding our global platform in 2018 and beyond,” he concluded.

About Colliers International
Colliers International Group Inc. (NASDAQ:CIGI) (TSX:CIGI) is an industry-leading real estate services company with a global brand operating in 69 countries and a workforce of more than 12,000 skilled professionals serving clients in the world’s most important markets. Colliers is the fastest-growing publicly listed global real estate services company, with 2017 corporate revenues of $2.3 billion ($2.7 billion including affiliates). With an enterprising culture and significant employee ownership and control, Colliers professionals provide a full range of services to real estate occupiers, owners and investors worldwide. Services include strategic advice and execution for property sales, leasing and finance; global corporate solutions; property, facility and project management; workplace solutions; appraisal, valuation and tax consulting; customized research; and thought leadership consulting.

Colliers professionals think differently, share great ideas and offer thoughtful and innovative advice that help clients accelerate their success. Colliers has been ranked among the top 100 global outsourcing firms by the International Association of Outsourcing Professionals for 13 consecutive years, more than any other real estate services firm. Colliers has also been ranked the number one property manager in the world by Commercial Property Executive for two years in a row.

For the latest news from Colliers, visit Colliers.com or follow us on Twitter: @Colliers and LinkedIn.

Consolidated Revenues by Line of Service

	Three months ended
(in thousands of US$)	March 31				Growth		Growth
(LC = local currency)	2018		2017		in USD %		in LC %
Outsourcing & Advisory	$	241,730	$	199,018	21	%	15	%
Lease Brokerage		167,734		144,827	16	%	12	%
Sales Brokerage		143,009		122,418	17	%	13	%
Total revenues	$	552,473	$	466,263	18	%	14	%

Consolidated revenues for the first quarter grew 14% on a local currency basis, led by a significant increase in Outsourcing & Advisory revenues in the EMEA region mainly attributable to the recent acquisition of a Finnish property and asset management firm. Consolidated internal revenue growth in local currencies was 6% (note 3), led by double-digit internal growth in Sales and Lease Brokerage in the Asia Pacific region.

Segmented Quarterly Results
Americas region revenues totalled $328.5 million for the first quarter compared to $283.8 million in the prior year quarter, up 15% on a local currency basis. Revenue growth was comprised of 8% contribution from recent acquisitions and 7% internal growth spread evenly across all three service lines. Adjusted EBITDA was $26.5 million, relative to $22.4 million in the prior year quarter. GAAP operating earnings were $20.0 million, relative to $12.7 million in the prior year quarter, with the prior year period impacted by acquisition-related costs.

EMEA region revenues totalled $115.7 million for the first quarter compared to $90.8 million in the prior year quarter, up 11% on a local currency basis, comprised of 13% growth from recent acquisitions offset by a 2% decline in internal revenues. Internal revenues were impacted by a decline in Sales Brokerage activity, primarily in the UK, relative to strong results reported in the prior year period, with activity levels also impacted by timing which is expected to increase future quarters’ revenues. Adjusted EBITDA was a loss of $0.4 million, versus a profit of $3.7 million in the prior year quarter, driven by planned investments in incremental revenue producers in major markets as well as revenue mix. The GAAP operating loss was $9.6 million for the quarter, relative to a loss of $1.0 million in the prior year quarter, with the current period impacted by acquisition-related costs and incremental acquisition-related amortization.

Asia Pacific region revenues totalled $107.8 million for the first quarter compared to $91.2 million in the prior year quarter, up 14% on a local currency basis. Revenue growth was comprised of 12% internal growth concentrated in Sales Brokerage and Lease Brokerage, and 2% growth from recent acquisitions. Adjusted EBITDA was $11.2 million versus $6.9 million in the prior year quarter, benefitting from operating leverage attributable to higher revenues resulting from investments in personnel in Asia over the last two years. GAAP operating earnings were $9.4 million for the first quarter, relative to $5.5 million in the prior year quarter.

Global corporate costs as reported in Adjusted EBITDA were $1.1 million in the first quarter, relative to $1.8 million in the prior year period, positively impacted by lower variable expenses. The corporate GAAP operating loss for the first quarter was $4.1 million, relative to a loss of $4.4 million in the prior year period.

Adoption of New Revenue Guidance
The Company adopted new US GAAP revenue guidance effective January 1, 2018, which had the impact of (i) increasing the proportion of reimbursable expenses related to property management activities accounted for as revenue on a gross basis, with no impact on earnings and (ii) accelerating the recognition of revenue related to certain Lease Brokerage transactions, with an accompanying immaterial increase to earnings.

In connection with the adoption, the Company restated its results for the prior year first quarter ended March 31, 2017 with the following impact:

• Increase to revenue of $43.4 million
• Increase to adjusted EBITDA of $2.0 million
• Increase to operating earnings of $2.0 million
• Increase to adjusted EPS of $0.04
• Increase to diluted net earnings per common share of $0.04

Conference Call
Colliers will be holding a conference call on Tuesday, May 1, 2018 at 11:00 a.m. Eastern Time to discuss the quarter’s results. The call, as well as a supplemental slide presentation, will be simultaneously web cast and can be accessed live or after the call at www.colliers.com in the “Shareholders / Newsroom” section.

Forward-looking Statements
This press release includes or may include forward-looking statements. Forward-looking statements include the Company’s financial performance outlook and statements regarding goals, beliefs, strategies, objectives, plans or current expectations. These statements involve known and unknown risks, uncertainties and other factors which may cause the actual results to be materially different from any future results, performance or achievements contemplated in the forward-looking statements. Such factors include: economic conditions, especially as they relate to commercial and consumer credit conditions and business spending; commercial real estate property values, vacancy rates and general conditions of financial liquidity for real estate transactions; the effects of changes in foreign exchange rates in relation to the US dollar on Canadian dollar, Australian dollar, UK pound sterling and Euro denominated revenues and expenses; competition in markets served by the Company; labor shortages or increases in commission, wage and benefit costs; disruptions or security failures in information technology systems; and political conditions or events, including elections, referenda, changes to international trade and immigration policies, and any outbreak or escalation of terrorism or hostilities.

Additional factors and explanatory information are identified in the Company’s Annual Information Form for the year ended December 31, 2017 under the heading “Risk Factors” (which factors are adopted herein and a copy of which can be obtained at www.sedar.com) and other periodic filings with Canadian and US securities regulators. Forward looking statements contained in this press release are made as of the date hereof and are subject to change. All forward-looking statements in this press release are qualified by these cautionary statements. Except as required by applicable law, Colliers undertakes no obligation to publicly update or revise any forward-looking statement, whether as a result of new information, future events or otherwise.

Summary financial information is provided in this press release. This press release should be read in conjunction with the Company's quarterly financial statements and MD&A to be made available on SEDAR at www.sedar.com.

Notes
1. Reconciliation of net earnings to adjusted EBITDA:

Adjusted EBITDA is defined as net earnings, adjusted to exclude: (i) income tax; (ii) other expense (income); (iii) interest expense; (iv) depreciation and amortization; (v) acquisition-related items; (vi) restructuring costs and (vii) stock-based compensation expense. We use adjusted EBITDA to evaluate our own operating performance and our ability to service debt, as well as an integral part of our planning and reporting systems. Additionally, we use this measure in conjunction with discounted cash flow models to determine the Company’s overall enterprise valuation and to evaluate acquisition targets. We present adjusted EBITDA as a supplemental measure because we believe such measure is useful to investors as a reasonable indicator of operating performance because of the low capital intensity of the Company’s service operations. We believe this measure is a financial metric used by many investors to compare companies, especially in the services industry. This measure is not a recognized measure of financial performance under GAAP in the United States, and should not be considered as a substitute for operating earnings, net earnings or cash flow from operating activities, as determined in accordance with GAAP. Our method of calculating adjusted EBITDA may differ from other issuers and accordingly, this measure may not be comparable to measures used by other issuers. A reconciliation of net earnings to adjusted EBITDA appears below.

	Three months ended
(in thousands of US$)	March 31
	2018			2017
Net earnings	$	8,541		$	6,800
Income tax		4,716			4,327
Other income, net		(427	)		(1,229	)
Interest expense, net		2,915			2,942
Operating earnings		15,745			12,840
Depreciation and amortization		15,858			12,027
Acquisition-related items		2,253			4,208
Restructuring costs		70			734
Stock-based compensation expense		2,214			1,443
Adjusted EBITDA	$	36,140		$	31,252

2. Reconciliation of net earnings and diluted net earnings (loss) per common share to adjusted net earnings and adjusted earnings per share:

Adjusted earnings per share is defined as diluted net earnings (loss) per common share, adjusted for the effect, after income tax, of: (i) the non-controlling interest redemption increment; (ii) amortization expense related to intangible assets recognized in connection with acquisitions; (iii) acquisition-related items; (iv) restructuring costs and (v) stock-based compensation expense. We believe this measure is useful to investors because it provides a supplemental way to understand the underlying operating performance of the Company and enhances the comparability of operating results from period to period. Adjusted earnings per share is not a recognized measure of financial performance under GAAP, and should not be considered as a substitute for diluted net earnings per share, as determined in accordance with GAAP. Our method of calculating this non-GAAP measure may differ from other issuers and, accordingly, this measure may not be comparable to measures used by other issuers. A reconciliation of net earnings to adjusted net earnings and of diluted net earnings (loss) per share to adjusted earnings per share appears below.

	Three months ended
(in thousands of US$)	March 31
	2018			2017
Net earnings	$	8,541		$	6,800
Non-controlling interest share of earnings		(670	)		(2,202	)
Amortization of intangible assets		8,588			6,050
Acquisition-related items		2,253			4,208
Restructuring costs		70			734
Stock-based compensation expense		2,214			1,443
Income tax on adjustments		(2,423	)		(2,010	)
Non-controlling interest on adjustments		(844	)		(844	)
Adjusted net earnings	$	17,729		$	14,179
	Three months ended
(in US$)	March 31
	2018			2017
Diluted net earnings per common share	$	0.13		$	0.04
Non-controlling interest redemption increment		0.07			0.08
Amortization of intangible assets, net of tax		0.14			0.09
Acquisition-related items		0.05			0.10
Restructuring costs, net of tax		-			0.01
Stock-based compensation expense, net of tax		0.06			0.04
Adjusted earnings per share	$	0.45		$	0.36

3. Local currency revenue growth rate and internal revenue growth

Percentage revenue variances presented on a local currency basis are calculated by translating the current period results of our non-US dollar denominated operations to US dollars using the foreign currency exchange rates from the periods against which the current period results are being compared. Percentage revenue variances presented on an internal growth basis are calculated assuming acquired entities were owned for the entire current period as well as the entire prior period. Revenue from acquired entities is estimated based on the operating performance of each acquired entity for the year prior to the acquisition date. We believe that these revenue growth rate methodologies provide a framework for assessing the Company’s performance and operations excluding the effects of foreign currency exchange rate fluctuations and acquisitions. Since these revenue growth rate measures are not calculated under GAAP, they may not be comparable to similar measures used by other issuers.

COLLIERS INTERNATIONAL GROUP INC.
Condensed Consolidated Statements of Earnings
(in thousands of US dollars, except per share amounts)
			Three months
			ended March 31
(unaudited)			2018			2017 (1)
Revenues		$	552,473		$	466,263
Cost of revenues			362,300			300,106
Selling, general and administrative expenses			156,317			137,082
Depreciation			7,270			5,977
Amortization of intangible assets			8,588			6,050
Acquisition-related items (2)			2,253			4,208
Operating earnings			15,745			12,840
Interest expense, net			2,915			2,942
Other income, net			(427	)		(1,229	)
Earnings before income tax			13,257			11,127
Income tax expense			4,716			4,327
Net earnings			8,541			6,800
Non-controlling interest share of earnings			670			2,202
Non-controlling interest redemption increment			2,905			3,220
Net earnings attributable to Company		$	4,966		$	1,378
Net earnings per common share
	Basic	$	0.13		$	0.04
	Diluted		0.13			0.04
Adjusted earnings per share (3)		$	0.45		$	0.36
Weighted average common shares (thousands)
	Basic		39,048			38,720
	Diluted		39,653			39,117

Notes to Condensed Consolidated Statements of Earnings
(1)  Restated to reflect adoption of new US GAAP revenue guidance effective January 1, 2018.
(2)  Acquisition-related items include transaction costs, contingent acquisition consideration fair value adjustments, and contingent acquisition consideration-related compensation expense.
(3)  See definition and reconciliation above.

Condensed Consolidated Balance Sheets
(in thousands of US dollars)
(unaudited)		March 31, 2018		December 31, 2017		March 31, 2017
Assets
Cash and cash equivalents		$	111,649	$	108,523	$	97,695
Accounts receivable and contract assets			439,732		487,279		380,148
Prepaids and other assets			80,275		68,556		55,611
	Current assets		631,656		664,358		533,454
Other non-current assets			73,445		72,736		63,189
Fixed assets			84,275		83,899		69,169
Deferred income tax			45,560		48,401		65,210
Goodwill and intangible assets			743,364		638,166		586,145
	Total assets	$	1,578,300	$	1,507,560	$	1,317,167
Liabilities and shareholders' equity
Accounts payable and accrued liabilities		$	502,478	$	646,722	$	418,345
Other current liabilities			59,483		75,494		54,086
Long-term debt - current			3,262		2,426		2,618
	Current liabilities		565,223		724,642		475,049
Long-term debt - non-current			433,261		247,467		402,370
Other liabilities			79,575		67,904		65,840
Deferred income tax			26,582		19,044		16,868
Redeemable non-controlling interests			153,125		145,489		121,846
Shareholders' equity			320,534		303,014		235,194
	Total liabilities and equity	$	1,578,300	$	1,507,560	$	1,317,167
Supplemental balance sheet information
Total debt		$	436,523	$	249,893	$	404,988
Total debt, net of cash			324,874		141,370		307,293
Net debt / pro forma adjusted EBITDA ratio			1.3		0.6		1.4

Consolidated Statements of Cash Flows
(in thousands of US dollars)
			Three months ended
			March 31
(unaudited)			2018			2017
Cash provided by (used in)
Operating activities
Net earnings		$	8,541		$	6,800
Items not affecting cash:
	Depreciation and amortization		15,858			12,027
	Deferred income tax		(393	)		1,847
	Other		7,826			8,220
			31,832			28,894
Net changes from operating assets / liabilities
	Accounts receivable		51,265			32,982
	Prepaids and other current assets		4,856			(9,614	)
	Payables and accruals		(164,549	)		(136,647	)
	Other		(738	)		3,148
	Contingent acquisition consideration paid		(2,856	)		(301	)
Net cash used in operating activities			(80,190	)		(81,538	)
Investing activities
Acquisition of businesses, net of cash acquired			(79,732	)		(29,643	)
Purchases of fixed assets			(6,209	)		(6,733	)
Other investing activities			(4,462	)		(10,596	)
Net cash used in investing activities			(90,403	)		(46,972	)
Financing activities
Increase in long-term debt, net			186,833			140,137
Purchases of non-controlling interests, net			(73	)		(24,282	)
Dividends paid to common shareholders			(1,947	)		(1,932	)
Distributions paid to non-controlling interests			(5,204	)		(4,118	)
Other financing activities			(2,519	)		(61	)
Net cash provided by financing activities			177,090			109,744
Effect of exchange rate changes on cash			(3,371	)		3,313
Increase (decrease) in cash and cash equivalents			3,126			(15,453	)
Cash and cash equivalents, beginning of period			108,523			113,148
Cash and cash equivalents, end of period		$	111,649		$	97,695

Segmented Results
(in thousands of US dollars)
							Asia
(unaudited)		Americas		EMEA			Pacific		Corporate			Consolidated
Three months ended March 31
2018
	Revenues	$	328,502	$	115,717		$	107,835	$	419		$	552,473
	Adjusted EBITDA		26,455		(431	)		11,217		(1,101	)		36,140
	Operating earnings (loss)		20,006		(9,571	)		9,374		(4,064	)		15,745
2017 (1)
	Revenues	$	283,822	$	90,771		$	91,200	$	470		$	466,263
	Adjusted EBITDA		22,435		3,701			6,896		(1,780	)		31,252
	Operating earnings (loss)		12,694		(975	)		5,511		(4,390	)		12,840

(1) Restated to reflect adoption of new US GAAP revenue guidance effective January 1, 2018.

COMPANY CONTACTS:

Jay S. Hennick
Chairman & CEO
                       
John B. Friedrichsen
CFO

(416) 960-9500

EX-99.2

EXHIBIT 99.2

Colliers International Group Inc. First Quarter 2018 Financial Results May 1, 2018

Forward - Looking Statements 2 This presentation includes or may include forward - looking statements. Forward - looking statements include the Company’s financial performance outlook and statements regarding goals, beliefs, strategies, objectives, plans or current expectations. These statements involve known and unknown risks, uncertainties and other factors which may cause the actual results to be materially different from any future results, performance or achievements contemplated in the forward - looking statements. Such factors include: economic conditions, especially as they relate to commercial and consumer credit conditions and business spending; commercial real estate property values, vacancy rates and general conditions of financial liquidity for real estate transactions; the effects of changes in foreign exchange rates in relation to the US dollar on Canadian dollar, Australian dollar, UK pound sterling and Euro denominated revenues and expenses; competition in markets served by the Company; labor shortages or increases in commission, wage and benefit costs; disruptions or security failures in information technology systems; and political conditions or events, including elections, referenda, changes to international trade and immigration policies and any outbreak or escalation of terrorism or hostilities. Additional factors and explanatory information are identified in the Company’s Annual Information Form for the year ended December 31, 2017 under the heading “Risk Factors” (which factors are adopted herein and a copy of which can be obtained at www.sedar.com ) and other periodic filings with Canadian and US securities regulators. Forward looking statements contained in this presentation are made as of the date hereof and are subject to change. All forward - looking statements in this press release are qualified by these cautionary statements. Except as required by applicable law, Colliers undertakes no obligation to publicly update or revise any forward - looking statement, whether as a result of new information, future events or otherwise. Non - GAAP measures This presentation makes reference to the non - GAAP measures Adjusted EBITDA and Adjusted EPS. Please refer to Colliers International 2018 Appendix for reconciliations to GAAP measures.

Colliers International 2018 ▪ Strong first quarter results, with balanced revenue growth from acquisitions and internally ▪ Quarterly revenues up 18% (14% in local currencies) with internal growth of 6% ▪ Adjusted EPS of $0.45, up 25% from the prior year quarter ▪ Expanded revolving credit facility to $1.0 billion, extended maturity to April 2023 and improved pricing by 25 basis points across the leverage grid ▪ Total of five acquisitions completed so far this year, three acquisitions in the first quarter ▪ Q1 2018 results reflect the adoption of new US GAAP revenue recognition standard; immaterial impact to earnings. Q1 2017 results have been restated for the impact of the adoption. First Quarter 2018 Results 3

Colliers International 2018 4 First Quarter 2018 Results Summary (US$ millions, except per share amounts) (1) Local currency (“LC”) basis, excluding the effects of foreign currency exchange rate fluctuations. USD LC (1) Revenue 552 . 5 466.3 18% 14% Adjusted EBITDA 36 . 1 31.3 16% 14% Adjusted EBITDA Margin 6 . 5% 6.7% Adjusted EPS 0 . 45 0.36 25% GAAP Operating Earnings 15 . 7 12.8 23% GAAP Operating Earnings Margin 2 . 8% 2.8% GAAP EPS 0 . 13 0.04 225% Q1 2018 Q1 2017 % Change over Q1 2017

Colliers International 2018 167.7 144.8 143.0 122.4 241.7 199.0 2 0 18 2 0 17 5 Outsourcing & Advisory (1) Sales Brokerage Lease Brokerage Q1 Revenue 552.5 466 . 3 First Quarter 2018 Consolidated Revenues (US$ millions) (1) Outsourcing & Advisory services include: Corporate Solutions, Valuation & Advisory Services, Property and Asset Management Services, Project Management, Workplace Solutions, Property Marketing and Research Services. % Change over Q1 2017 U S D L C Total 18% 14% Outsourcing & Advisory 21% 15% Sales Brokerage 17% 13% Lease Brokerage 16% 12% Revenue Mix Q1 2018 Q1 2017 Outsourcing & Advisory 44% 43% Sales Brokerage 26% 26% Lease Brokerage 30% 31% Total 100% 100%

Colliers International 2018 6 Q1 2018 Adjusted EBITDA (1) First Quarter Geographic Split (US$ millions) Q1 2018 Revenue (1) Q1 2018 GAAP Operating Earnings (Loss): $20.0M Americas, ($9.6M) EMEA, $9.4M Asia Pacific (2) Q1 2017 GAAP Operating Earnings (Loss): $12.7M Americas, ($1.0M) EMEA, $5.5M Asia Pacific 59 % 21 % 20 % A m e r i c a s 328.5 E M EA 115 . 7 Asia Pacific 107.8 A m e r i c a s 283.8 E M EA 90.8 Q1 2017 Revenue Asia Pacific 91.2 61 % 19 % 20 % A m e r i c a s 26.5 E M EA (0.4) Asia Pacific 11.2 71 % - 1 % 30 % 68 % 11 % 21 % A m e r i c a s 22.4 E M EA 3.7 Q1 2017 Adjusted EBITDA (2) Asia Pacific 6.9

Colliers International 2018 7 R e v e nue Amer i cas (US$ millions) ▪ Revenues up 15% in local currencies, with 8% growth from recent acquisitions and 7% from internal growth ▪ Internal growth was spread evenly across all three service lines, with strong contribution from Canadian operations ▪ Adjusted EBITDA up 18% with margin improvement from operating leverage Outsourcing & Advisory (1) Sales Brokerage Lease Brokerage (1) Outsourcing & Advisory services include: Corporate Solutions, Valuation & Advisory Services, Property and Asset Management Services, Project Management, Workplace Solutions, Property Marketing and Research Services. (2) GAAP Operating Earnings: Q1 2018 $20.0M at 6.1% margin ; Q1 2017 $12.7M at 4.5% margin Adjusted EBITDA (2) (Adjusted EBITDA Margin) U S D L C Internal Growth (LC) Revenue Growth 16% 15% 7% 328.5 119.5 283.8 103.5 88.6 75.9 120.4 104.4 Q1 2018 Q1 2017 26 . 5 22 . 4 8.1% 7.9% Q1 2018 Q1 2017

Colliers International 2018 3 . 7 115.7 68.2 90.8 49.8 23.6 20.4 23.9 20.6 Q1 2018 8 R e v e nue EMEA (US$ millions) ▪ Revenues up 11% in local currencies, 13% growth from recent acquisitions offset by a 2% decline in internal revenues ▪ Internal revenues were impacted by a decline in Sales Brokerage activity, primarily in the UK, relative to the strong results reported in the prior year period ▪ Pipelines in the UK, Germany and other major markets in the region remain solid ▪ Adjusted EBITDA decline driven by planned investments in incremental revenue producers in major markets as well as revenue mix Outsourcing & Advisory (1) Sales Brokerage Lease Brokerage (1) Outsourcing & Advisory services include: Corporate Solutions, Valuation & Advisory Services, Property and Asset Management Services, Project Management, Workplace Solutions, Property Marketing and Research Services. (2) GAAP Operating Loss: Q1 2018 ($9.6M) at - 6.1% margin ; Q1 2017 ($1.0M) at - 1.1% margin Adjusted EBITDA (2) (Adjusted EBITDA Margin) (0.4) Q1 2018 Q1 2017 4.1% - 0.4% U S D L C Q1 2017 Internal Growth (LC) Revenue Growth 27% 11% - 2%

Colliers International 2018 ▪ Revenues up 14% in local currencies, with 12% from internal growth and 2% growth from a recent acquisition ▪ Internal growth was driven by notable increases in Sales Brokerage activity in Hong Kong and China as well as strong Lease Brokerage throughout the region, including Australia and New Zealand ▪ Adjusted EBITDA reflects operating leverage due to revenue growth, particularly in Hong Kong and China 107.8 53.5 91.2 45.3 30.8 26 . 0 23.5 19 . 9 Q1 2018 9 R e v e nue Asia Pacific (US$ millions) Outsourcing & Advisory (1) Sales Brokerage Lease Brokerage (1) Outsourcing & Advisory services include: Corporate Solutions, Valuation & Advisory Services, Property and Asset Management Services, Project Management, Workplace Solutions, Property Marketing and Research Services. (2) GAAP Operating Earnings: Q1 2018 $9.4M at 8.7% margin ; Q1 2017 $5.5M at 6.0% margin Adjusted EBITDA (2) (Adjusted EBITDA Margin) U S D L C Q1 2017 Internal Growth (LC) Revenue Growth 18% 14% 12% 11 . 2 6 .9 10.4% 7.6% Q1 2018 Q1 2017

Colliers International 2018 10 Highlights ▪ Net debt / pro forma adjusted EBITDA leverage of 1.3x at March 31, 2018 down from 1.4x in the prior year comparable period ▪ Strong first quarter acquisition momentum continued subsequent to quarter end with Salt Lake City and Winnipeg acquisitions ▪ Expanded ($1 billion capacity) and extended (April 2023) credit facility provides ample capacity for future growth ▪ Anticipated capital expenditures of $40 - 42 million for full year 2018 Capitalization & Capital Allocation Overview (US$ millions) (1) Includes business acquisitions, contingent acquisition consideration and purchases of non - controlling interests in subsidiaries. C a s h Total Debt 405.0 $ 307.3 145.5 121.8 Net Debt Redeemable non - controlling interests Shareholders' equity 303.0 235.2 $ 589.9 $ 664.3 Total capitalization Net debt / pro forma adjusted EBITDA 1 .3 0 .6 1 .4 Capital Expenditures Acquisition Spend (1) March 31, 2018 December 31, 2017 $ 108 . 5 249 . 9 $ 141 . 4 March 31, 2017 $ 97.7 3 Months Ended March 31, 2018 $ 6.2 $ 87.8 March 31, 2017 $ 6.7 $ 55.9 $ 111 . 6 436 . 5 $ 324 . 9 153 . 1 320 . 5 $ 798.5

Colliers International 2018 ▪ 2018 Outlook o Predicated on stable market conditions, including modest economic growth and increases to interest rates o Low to mid single - digit percentage internal revenue growth on full year basis plus mid single - digit revenue growth due to acquisitions o Adjusted EBITDA margin improvement of 20 - 30 bps o Consolidated income tax rate of 30 - 32% (including benefit of lower corporate tax rates under US Tax Reform) o Low to mid teen percentage adjusted EPS growth on full year basis o Future acquisitions would be incremental to growth assumptions above ▪ Enterprise 2020 Plan o In year 3 of 5 year plan, Colliers remains on - track to achieving growth targets Looking Ahead 11

Appendix: Reconciliation of non - GAAP measures

Colliers International 2018 Reconciliation of GAAP earnings to adjusted EBITDA 13 (US$ thousands) Three months ended March 31, 2018 March 31, 2017 Net earnings $ 8 , 541 $ 6 , 800 Income tax 4 , 716 4 , 327 Other income, net ( 427) ( 1 , 229) Interest expense, net 2 , 915 2 , 942 Operating earnings 15 , 745 12 , 840 Depreciation and amortization 15 , 858 12 , 027 Acquisition - related items 2 , 253 4 , 208 Restructuring costs 70 734 Stock - based compensation expense 2 , 214 1 , 443 Adjusted EBITDA $ 36 , 140 $ 31 , 252

Reconciliation of GAAP earnings to adjusted net earnings and adjusted earnings per share Three months ended (US$ thousands) March 31, 2018 March 31, 2017 Net earnings $ 8 , 541 $ 6 , 800 Non - controlling interest share of earnings ( 670) ( 2 , 202) Amortization of intangible assets 8 , 588 6 , 050 Acquisition - related items 2 , 253 4 , 208 Restructuring costs 70 734 Stock - based compensation expense 2 , 214 1 , 443 Income tax on adjustments ( 2 , 423) ( 2 , 010) Non - controlling interest on adjustments ( 844) ( 844) Adjusted net earnings $ 17 , 729 $ 14 , 179 Three months ended (US$) March 31, 2018 March 31, 2017 Diluted net earnings $ 0 . 13 $ 0.04 Non - controlling interest redemption increment 0 . 07 0 . 08 Amortization of intangible assets, net of tax 0 . 14 0 . 09 Acquisition - related items 0 . 05 0 . 10 Restructuring costs, net of tax - 0 . 01 Stock - based compensation expense, net of tax 0 . 06 0 . 04 Adjusted EPS $ 0 . 45 $ 0.36 C olliers International 2018 14