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Exhibit 99.1

Contact:	Scott A. Montgomery	David R. Brown
	President/CEO	Executive Vice President and
	National Mercantile Bancorp	Chief Financial Officer
	(310) 282-6778	(310) 282-6703

FOR IMMEDIATE RELEASE

NATIONAL MERCANTILE BANCORP ANNOUNCES ITS RESULTS
FOR THE PERIOD ENDED SEPTEMBER 30, 2001 AND THAT IT
HAS RECEIVED OCC APPROVAL TO ACQUIRE SOUTH BAY BANK, N.A.

    Los Angeles, California, October 26, 2001—National Mercantile Bancorp (the "Company") (NASDAQ: MBLA—Common Stock; MBLAP—Preferred Stock), parent company of Mercantile National Bank ("Bank"), today reported a loss of $197,000 for the third quarter ended September 30, 2001, or $0.12 basic and fully diluted loss per share, as compared to core earnings of $632,000 or $0.64 basic earnings per share ("EPS") and $0.24 diluted EPS for the third quarter ended September 30, 2000.

    For the nine months ended September 30, 2001, the Company reported net income of $1.0 million or $0.63 basic EPS, while diluted EPS is $0.31 as compared to net income of $1.6 million, excluding the reverse provision for credit losses during the second quarter of 2000, or $1.77 basic EPS and $0.62 diluted EPS for the nine months ended September 30, 2000.

    On October 18, 2001, the Office of the Comptroller of the Currency ("OCC") approved the acquisition of South Bay Bank. The acquisition, which had been previously announced, is expected to close in early November. Upon closing of the transaction, the shareholders of South Bay Bank will receive approximately $29.1 million (approximately $10.325 per share in cash) and South Bay Bank will become a wholly-owned subsidiary of the Company. The purchase price represents approximately 1.93 times the book value of South Bay Bank. The business combination will be accounted for using the "purchase accounting method." The Company presently conducts its operations through one subsidiary, Mercantile National Bank, which was founded in 1982 and has offices in Los Angeles and Encino. South Bay Bank, with total assets of $188.5 million at September 30, 2001, has offices in Torrance and El Segundo. The merger will provide the Company four strategically located banking offices in the Los Angeles metropolitan area.

    Consummation of the acquisition of South Bay Bank is subject to a number of conditions, including receipt of approval of the Federal Reserve Board, and no assurance can be given that the acquisition will be completed.

    Mr. Montgomery commented, "We are excited about the opportunities that lie ahead with our acquisition of South Bay Bank. We believe that both banks will benefit from this transaction and that we will be able to enhance client service while expanding products such as home banking, cash management and ATMs."

    The loss reported for the third quarter of 2001 is a combination of four factors: (1) the substantial decline in interest rates narrowing margins (350 basis points in nine steps since the beginning of the year); (2) the net interest costs of $150,000 during the third quarter associated with the $15 million of trust preferred securities issued by the Company which closed on July 16, 2001. The proceeds of the trust preferred will be utilized in the acquisition of South Bay Bank. (3) The need to maintain a higher

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level of Federal Funds to ensure the Company has the liquidity to complete the purchase of South Bay Bank; and (4) a provision for loan losses of $450,000, the first such provision in five years.

    Mr. Montgomery commented, "While it is disappointing to report a loss, even a small loss such as this, the Company was profitable for the nine months ended September 30, 2001. We anticipate that both banks, Mercantile National Bank and South Bay Bank, will be profitable during the fourth quarter and for the full year. With the slowing economy and the events of September 11, 2001, it is difficult to fully anticipate the longer term economic impact. What is clear is that there is increased potential for higher loan losses, not just at the Company, but in the industry as a whole today. The provision for loan losses results from downgrading two loans. While these loans may be fully collectable in the future, we believe that these downgrades, coupled with a slowing economy, make increasing loan loss reserves prudent.

    We are also pleased to announce that in September the Company received the Bauerfinancial Reports' highest 5-star Superior rating. Bauerfinancial is an independent company, recognized nationally, that rates financial services companies and to receive their highest rating is very gratifying. As of October 19, 2001 our Website, www.mnbla.com, became fully operational. We invite our clients, shareholders and friends to utilize this new service."

    In comparing the results, it is important to keep in mind that during the second quarter of 2000, net income increased by $576,000 or $0.63 basic EPS and $0.22 diluted EPS, due to the reverse provision for credit losses in recognition of the level of the allowance for loan and lease losses ("ALLL") generated by a large loan recovery. To provide consistent quarter to quarter comparisons, the one time recovery, which nearly doubled the net income in the second quarter of 2000, is excluded on the statement of operations data and ratios in a third column which has been adjusted to reflect only core earnings for the nine months ended September 30, 2000.

Interest and Fee Income

    During the third quarter of 2001, total interest income decreased 16.3% to $3.3 million from $3.9 million during the third quarter of 2000 as rates declined. Interest income from investment securities decreased 43.2% to $679,000 from $1.2 million due to the planned reduction in the size of the securities portfolio and to increase liquidity in anticipation of the South Bay Bank acquisition.

    Other operating income increased by 40.2% from $199,000 during the quarter ended September 30, 2000 to $279,000 during the quarter ended September 30, 2001. The primary reason for the increase in non-interest income is attributable to gains on the sale of investment securities.

    For the nine months ended September 30, 2001 total interest income increased 1.4% or $148,000 to $10.5 million from $10.3 million at September 30, 2000. Other operating income increased 18.8% during this period from $685,000 to $814,000.

    Net interest margin decreased to 4.42% during the third quarter of 2001, down from 5.31% during the third quarter of 2000. The rapid reduction in rates by the Federal Reserve will continue to put pressure on margins for the remainder of the year.

Operating Expenses

    Other operating expenses increased 6.4% or by $126,000 during the third quarter of 2001, as compared to the third quarter of 2000. The increase was primarily the result of an increase in staff and benefits costs and costs associated with the Company's acquisition program.

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Assets and Liabilities

    Total assets increased 6.4% or $12.2 million to $204.0 million at September 30, 2001, as compared to $191.8 million at September 30, 2000. The growth in assets was primarily due to a $3.0 million or 3.0% increase in net loans receivable and a $31.4 million increase in federal funds sold, while investment securities decreased $23.6 million. The increase in liabilities was primarily due to a $11.2 million or 8.2% increase in deposits, while other borrowed funds declined $18.0 million, equity increased by $4.0 million while long term debt, which represents the trust preferred securities, increased $15.0 million.

Shareholders' Equity

    Shareholders' equity increased 21.3% or $4.0 million to $22.8 million at September 30, 2001 as compared to $18.8 million at September 30, 2000. Book value per share increased 17.5% from $6.01 per share at September 30, 2000 to $7.06 per share at September 30, 2001. The increase was the result of the net income during the twelve month period plus the increase in the estimated fair value of the investment securities portfolio due to decreased market interest rates during the latter part of 2000 and the first nine months of 2001.

    Generally Accepted Accounting Principles ("GAAP") require that securities held by the Bank and classified as available for sale ("AFS") be recorded at estimated fair value with the resulting unrealized gains or losses reflected as a separate component of shareholders' equity. If the investment securities were classified as held to maturity ("HTM"), no adjustment to equity, under GAAP, based on estimated fair value would have been required. The Bank carries its investment securities as AFS, as do many banks, in order to provide maximum flexibility. The Bank generally intends to hold its investment securities to maturity.

    The Company continues to benefit from the net operating loss carryforward ("NOL"), which was $18.4 million of carryforward benefit for federal income taxes and $1.5 million of carryforward benefit for state income taxes at December 31, 2000. The carryforward has the effect of substantially reducing income taxes which adds to the growth in equity. The Company's federal net operating loss carryforward is available through 2009, while the state tax carryforward continues to expire or will be fully utilized during 2001. As a result, the provision for income taxes, representing alternative minimum tax, was only $42,000 for the quarter ended September 30, 2001.

Credit Quality

    Total non-performing assets were $2.2 million at September 30, 2001 as compared to $596,000 at June 30, 2001 and $683,000 at September 30, 2000. The increase is directly related to downgrading two loans. During the third quarter of 2001 loan charge-offs were $22,000, while recoveries were $109,000, resulting in net recoveries of $87,000.

    As a result of the increased loan loss provision during the third quarter of 2001, the allowance for loan and lease losses ("ALLL") increased as a percentage of loans receivable from 2.22% at June 30, 2001 to 2.78% at September 30, 2001, while the coverage ratios declined due to the increase in non-performing assets.

Third Quarter Performance Ratios

    The Company's efficiency ratio declined to 87.68% during the third quarter of 2001 from 75.20% during the third quarter of 2000. The primary reason for the decline was the impact of the reduction in interest rates, the interest cost associated with the trust preferred securities and the loan loss provision.

    Return on average assets ("ROAA") was adversely affected by the same issues and declined from 1.33% during the third quarter of 2000 to -0.39% during the third quarter of 2001. Return on average

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equity ("ROAE") was also adversely affected and declined from 17.49% during the third quarter of 2000 to -3.37% during the third quarter of 2001.

    For the nine months ended September 30, 2001, ROAA was 0.69% as compared to 1.23% for the nine months ended September 30, 2000, while ROAE declined from 16.83% to 6.05% during the same period.

    The Company's operating expense ratio declined from 4.46% for the nine months ended September 30, 2000 to 4.12% for the same period in 2001.

    This press release contains statements which constitute forward looking statements within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934 that involve risk and uncertainties. Actual results may differ materially from the results in these forward looking statements. Factors that might cause such a difference include, among other things, fluctuations in interest rates, changes in economic conditions or governmental regulation, credit quality and other factors discussed in the Company's Annual Report on Form 10-KSB for the year ended December 31, 2000.

    National Mercantile Bancorp is the holding company for Mercantile National Bank, member FDIC, a business bank located in Century City in west Los Angeles, California with a regional office/branch in Encino, California. The Bank offers a wide range of financial services to the entertainment industry, the professional, healthcare and executive markets, community-based non-profit organizations, escrow companies and the business banking market.

"Redefining Business Banking"

#####

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National Mercantile Bancorp
September 30, 2001—FINANCIAL SUMMARY
($ in 000's, except share data)

SELECTED FINANCIAL CONDITION DATA:

			September 30, 2001			June 30, 2001			March 31, 2001			December 31, 2000			September 30, 2000			December 31, 1999
			(Unaudited)			(Unaudited)			(Unaudited)						(Unaudited)
Cash and Due from Banks			$	10,525		$	11,959		$	9,316		$	7,897		$	9,711		$	5,789
Federal Funds Sold and Securities Purchased under Agreements to Resell				43,950			34,000			28,900			19,700			12,550			4,450
Investment Securities-AFS, at Fair Value				44,984			51,971			63,117			67,150			68,599			71,235
Loans
	Commercial			97,611			100,592			101,361			104,960			96,639			71,581
	Real Estate Construction and Land			3,500			2,931			2,344			1,890			1,079			6
	Consumer and Others			3,588			3,327			3,636			3,729			3,753			2,496
		Deferred Loan Fees, Net		(188	)		(180	)		(232	)		(331	)		(283	)		(240	)
		Total		104,511			106,670			107,109			110,248			101,188			73,843
		Allowance for Credit Losses		(2,901	)		(2,363	)		(2,452	)		(2,597	)		(2,585	)		(1,896	)
	Net Loans			101,610			104,307			104,657			107,651			98,603			71,947
Other Assets				2,968			2,234			2,437			2,445			2,342			2,732
Total Assets			$	204,037		$	204,471		$	208,427		$	204,843		$	191,805		$	156,153
Deposits
	Demand, Non-interest Bearing		$	63,794		$	60,092		$	61,545		$	59,935		$	56,922		$	53,827
	NOW			11,241			9,280			7,644			9,004			6,925			8,669
	MMDA			39,736			39,400			34,038			32,351			40,707			25,376
	Savings			1,483			1,263			1,344			1,144			1,066			3,079
	Time Certificates > $100			27,824			33,092			33,144			25,865			25,082			19,488
	Time Certificates < $100			4,177			3,387			6,266			6,248			6,375			6,545
		Total Deposits		148,255			146,514			143,981			134,547			137,077			116,984
Securities Sold under Agreements to Repurchase and Other Borrowed Funds				16,000			34,000			41,000			47,500			34,000			26,200
Long-Term Debt				15,000			—			—			—			—			—
Other Liabilities				1,947			1,628			1,561			2,093			1,904			1,382
Shareholders' Equity				22,448			22,634			21,905			21,239			20,435			14,062
Accumulated Other Comprehensive Gain (Loss)				387			(305	)		(20	)		(536	)		(1,611	)		(2,475	)
Total Liabilities and Stockholders' Equity			$	204,037		$	204,471		$	208,427		$	204,843		$	191,805		$	156,153
Average Quarterly Assets
	Holding Company		$	202,510		$	190,372		$	195,666		$	196,512		$	188,864		$	154,671
	Bank		$	198,330		$	187,258		$	192,616		$	193,589		$	187,254		$	153,631
Regulatory Capital-Tier I
	Holding Company		$	29,930		$	22,634		$	21,905		$	21,239		$	20,435		$	14,062
	Bank		$	19,226		$	19,259		$	18,696		$	18,150		$	17,437		$	12,949
Non-Performing Assets
	Non-Accrual Loans		$	2,178		$	449		$	477		$	683		$	683		$	932
	Loans 90 Days P/D & Accruing			—			147			—			—			—			—
	OREO and Other Non-perfoming Assets			—			—			—			—			—			532
Total Non-Performing Assets			$	2,178		$	596		$	477		$	683		$	683		$	1,464

SELECTED STATEMENT OF FINANCIAL CONDITION RATIOS:

		September 30, 2001			June 30, 2001			March 31, 2001			December 31, 2000			September 30, 2000			December 31, 1999
		(Unaudited)			(Unaudited)			(Unaudited)						(Unaudited)
Loans to Deposits Ratio			70.49	%		72.81	%		74.39	%		81.94	%		73.82	%		63.12	%
Ratio of Allowance for Loan Losses to:
	Total Loans		2.78	%		2.22	%		2.29	%		2.36	%		2.55	%		2.57	%
	Total Non-Performing Assets		133.20	%		396.48	%		514.05	%		380.23	%		378.48	%		129.51	%
Earning Assets to Total Assets			94.81	%		94.21	%		95.54	%		96.22	%		95.06	%		95.76	%
Earning Assets to Interest-Bearing Liabilities			192.56	%		159.97	%		161.32	%		161.41	%		159.73	%		167.34	%
Capital Ratios Holding Company:
	Total Risk-Based Capital		31.92	%		19.23	%		18.93	%		18.26	%		18.82	%		17.47	%
	Tier 1 Risk-Based Capital		24.50	%		17.97	%		17.67	%		17.00	%		17.56	%		16.21	%
	Tier 1 Leverage		14.79	%		11.88	%		11.19	%		10.73	%		10.69	%		8.98	%
Capital Ratios Bank:
	Total Risk-Based Capital		17.25	%		16.74	%		16.52	%		16.00	%		16.41	%		16.29	%
	Tier 1 Risk-Based Capital		15.99	%		15.48	%		15.26	%		14.74	%		15.15	%		15.03	%
	Tier 1 Leverage		9.70	%		10.28	%		9.70	%		9.31	%		9.20	%		8.32	%
Risk Weighted Assets:
	Holding Company	$	122,154		$	125,960		$	123,951		$	124,958		$	116,370		$	86,751
	Bank	$	120,235		$	124,408		$	122,493		$	123,175		$	115,090		$	86,125
Book Value per Share (1) (2)		$	7.06		$	6.92		$	6.83		$	6.52		$	6.01		$	4.68
Total Shares Outstanding (2)			3,123,665			3,121,815			3,101,442			3,088,275			3,082,170			2,477,195

(1)

Includes the effect of dilutive options and warrants.

(2)

Includes assumed conversion of 750,680 shares of Preferred Stock into 1,501,360 shares of Common Stock.

National Mercantile Bancorp
September 30, 2001—FINANCIAL SUMMARY
($ in 000's, except share data)

SELECTED STATEMENT OF OPERATIONS DATA AND RATIOS:

QUARTERLY DATA:	Third Quarter 2001			Second Quarter 2001			First Quarter 2001			Fourth Quarter 2000			Third Quarter 2000
	(Unaudited)			(Unaudited)			(Unaudited)			(Unaudited)			(Unaudited)
Interest Income	$	3,256		$	3,404		$	3,832		$	4,116		$	3,888
Interest Expense		1,140			1,031			1,303			1,451			1,462
Net Interest Income before Provision for Loan Losses		2,116			2,373			2,529			2,665			2,426
Provision for Loan Losses		450			—			—			—			—
Net Interest Income after Provision for Loan Losses		1,666			2,373			2,529			2,665			2,426
Net gain on Sale of Securities Available-for-Sale		92			96			50			—			—
Gain on Sale of OREO and Fixed Assets		—			—			—			—			—
Other Operating Income		187			230			159			183			199
Other Operating Expense		2,100			2,059			2,122			2,051			1,974
Net Income before Provision for Income Taxes		(155	)		640			616			797			651
Provision for Income Taxes		42			34			13			22			19
Net Income	$	(197	)	$	606		$	603		$	775		$	632
Basic Earnings Per Share	$	(0.12	)	$	0.38		$	0.38		$	0.50		$	0.64
Diluted Earnings Per Share	$	(0.12	)	$	0.19		$	0.19		$	0.24		$	0.24
Weighted Avg Common Shares O/S (3)		1,621,751			1,613,383			1,574,440			1,545,276			989,823
Return on Quarterly Average Assets		-0.39	%		1.28	%		1.25	%		1.57	%		1.33	%
Return on Quarterly Average Equity		-3.37	%		10.94	%		11.32	%		15.79	%		17.49	%
Net Interest Margin—Avg Earning Assets		4.42	%		5.31	%		5.54	%		5.64	%		5.31	%
Operating Expense Ratio		4.12	%		4.34	%		4.40	%		4.15	%		4.16	%
Efficiency Ratio		87.68	%		76.29	%		77.50	%		72.02	%		75.20	%

Quarterly operating ratios are annualized.

FOR THE NINE MONTHS ENDED SEPTEMBER 30:	2001			2000			Adjusted 2000(1)
Interest Income	$	10,492		$	10,344		$	10,344
Interest Expense		3,474			3,572			3,572
Net Interest Income before Provision for Loan Losses		7,018			6,772			6,772
Provision for Loan Losses		450			(576	)		—
Net Interest Income after Provision for Loan Losses		6,568			7,348			6,772
Net Gain (Loss) on Sale of Securities Available-for-Sale		238			18			18
Gain on Sale of OREO and Fixed Assets		—			69			69
Other Operating Income		576			598			598
Other Operating Expense		6,281			5,819			5,819
Net Income (Loss) before Provision for Income Taxes		1,101			2,214			1,638
Provision for Income Taxes		89			45			45
Net Income (Loss)	$	1,012		$	2,169		$	1,593
Basic Earnings Per Share	$	0.63		$	2.41		$	1.77
Diluted Earnings Per Share (2)	$	0.31		$	0.85		$	0.62
Weighted Avg Common Shares O/S (3) (4)		1,603,365			898,573			898,573
Return on Average Assets		0.69	%		1.67	%		1.23	%
Return on Average Equity		6.05	%		22.92	%		16.83	%
Net Interest Margin—Avg Earning Assets		5.08	%		5.42	%		5.42	%
Operating Expense Ratio		4.12	%		4.46	%		4.46	%
Efficiency Ratio		80.20	%		78.03	%		78.03	%

(1)

Adjusted for $576 thousand reverse provision for credit losses.

(2)

The weighted average number of common shares and common share equivalents outstanding used in computing diluted earnings per share for the nine months ended September 30, 2001 and 2000 was 3,232,543 and 2,556,196, respectively.

(3)

Shares used to compute Basic Earnings per share.

(4)

Increase from previous periods is due to issuance of Common Stock and conversion of Preferred Stock into Common Stock.

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Exhibit 99.1
National Mercantile Bancorp September 30, 2001—FINANCIAL SUMMARY ($ in 000's, except share data) SELECTED FINANCIAL CONDITION DATA
SELECTED STATEMENT OF FINANCIAL CONDITION RATIOS
National Mercantile Bancorp September 30, 2001—FINANCIAL SUMMARY ($ in 000's, except share data) SELECTED STATEMENT OF OPERATIONS DATA AND RATIOS