News Release
	Marshall & Ilsley Corporation   770 North Water Street/Milwaukee, Wisconsin 53202
For release:	Immediately
For further information:	John Presley, senior vice president, chief financial officer, (414) 765-7833 Don Wilson, senior vice president, corporate treasurer, (414) 765-8043

MARSHALL & ILSLEY CORPORATION ANNOUNCES FIRST QUARTER RESULTS

Milwaukee, Wis. – Apr. 12, 2005 – Marshall & Ilsley Corporation (NYSE: MI) today reported 2005 first quarter net income of $0.73 per diluted share, or $169.6 million, as compared to $0.65 per diluted share, or $146.1 million, in the first quarter of 2004. First quarter net income per share increased 12.3 percent over the same period in 2004.

Return on average assets based on net income for the first quarter was 1.68 percent, as compared to 1.69 percent for the same period in 2004.  Return on average equity based on net income was 17.28 percent this quarter as compared to 17.42 percent for the first quarter of 2004.  

The Corporation’s provision for loan and lease losses was $8.1 million in the first quarter of 2005, versus $9.0 million in the same period last year.  Net charge-offs for the period were $8.0 million, or 0.11 percent of total average loans and leases outstanding this quarter, and $4.9 million a year ago or 0.08 percent of total average loans and leases.  At March 31, 2005, the allowance for loan and lease losses was 1.17 percent of total loans and leases, compared to 1.36 percent a year earlier.  Nonperforming loans and leases were 0.42 percent of total loans and leases at March 31, 2005, and 0.60 percent at March 31, 2004.

Assets at March 31, 2005 were $41.6 billion, compared to $35.5 billion at March 31, 2004.  Book value per share was $17.71 at March 31, 2005, compared to $15.42 for the same date a year ago.  Total loans and leases were $30.6 billion, compared to $26.1 billion at March 31, 2004.

Marshall & Ilsley Corporation (NYSE: MI) is a diversified financial services corporation headquartered in Milwaukee, Wis., with $41.6 billion in assets. Founded in 1847, M&I Marshall & Ilsley Bank has the largest banking presence in Wisconsin with 196 offices throughout the state. In addition, M&I has 35 locations throughout Arizona; 11 offices in metropolitan Minneapolis/St. Paul, Minn.; and, locations in Duluth, Minn.; Las Vegas, Nev.; and, Naples and Bonita Springs, Fla. M&I’s Southwest Bank affiliate has six offices in the St. Louis area and one office in Belleville, Ill. Metavante Corporation, Marshall & Ilsley Corporation’s wholly owned technology subsidiary, provides virtually all of the technology an organization needs to offer financial services. M&I also provides trust and investment management, equipment leasing, mortgage banking, asset-based lending, financial planning, investments, and insurance services from offices throughout the country and on the Internet (www.mibank.com or www.micorp.com). M&I’s customer-based approach, internal growth, and strategic acquisitions have made M&I a nationally recognized leader in the financial services industry.

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This press release contains forward-looking statements concerning M&I’s future operations and financial results.  Such statements are subject to important factors that could cause M&I’s actual results to differ materially from those anticipated by the forward-looking statements.  These factors include (i) the factors identified in M&I’s Annual Report on Form 10-K for the year ended December 31, 2004 under the heading “Forward-Looking Statements” which factors are incorporated herein by reference, and (ii) such other factors as may be described from time to time in M&I’s SEC filings.

Note:

Marshall & Ilsley Corporation will hold a conference call at 11:00 a.m. Central Daylight Time Tuesday, April 12, regarding first quarter earnings.  For those interested in listening, please call 1-800-243-6403 and ask for M&I’s quarterly earnings release conference call.  If you are unable to join us at this time, a replay of the call will run through April 19, 5:00 p.m. Central Daylight Time by calling 1-800-839-6713 and entering passcode 700 88 47 to listen.

Supplemental financial information referenced in the conference call can be found at www.micorp.com, Investor Relations, after 8:00 a.m. on April 12.

M&I  Corporation
Financial Information
(unaudited)
	Three Months Ended
	March 31,		March 31,		Percent
	2005		2004		Change
PER SHARE DATA
Diluted:
Net  Income	$0.73		$0.65		12.3	%
Basic:
Net  Income	0.75		0.66		13.6
Dividend Declared	0.210		0.180		16.7
Book Value	17.71		15.42		14.9
Shares  Outstanding (millions):
Average - Diluted	231.6		226.0		2.5
End of Period	228.7		222.1		3.0
INCOME STATEMENT ($millions)
Net Interest Income (FTE)	$300.0		$286.5		4.7	%
Provision for Loan and Lease Losses	8.1		9.0		-10.0
Data Processing Services	272.4		186.1		46.4
Item Processing	10.6		11.4		-7.0
Trust Services	40.3		36.3		11.0
Service Charge on Deposits	23.6		25.5		-7.5
Mortgage Banking	8.0		6.9		15.9
Net Investment Securities Gains (Losses)	5.8		(0.5)		n.m.
All Other	48.8		47.7		2.3
Total Non-Interest Revenues	409.5		313.4		30.7
Salaries and Employee Benefits	238.5		203.9		17.0
Occupancy and Equipment	53.4		47.4		12.7
Intangible Amortization	8.1		5.5		47.3
Other	136.4		105.5		29.3
Total Non-Interest Expenses	436.4		362.3		20.5
Tax Equivalent Adjustment	8.2		7.9		3.8
Pre-Tax Earnings	256.8		220.7		16.4
Income Taxes	87.2		74.6		16.9
Net  Income	$169.6		$146.1		16.1	%
KEY  RATIOS
Net Interest Margin (FTE) / Avg. Earning Assets	3.36	%	3.69	%
Interest Spread (FTE)	2.97		3.39
Efficiency  Ratio	62.0		60.4
Efficiency  Ratio  without  Metavante	48.8		49.2
Return on Assets	1.68		1.69
Return on Equity	17.28		17.42
Equity / Assets (End of Period)	9.66		9.59
M&I  Corporation
Financial Information
(unaudited)
	As of
	March 31,		March 31,		Percent
ASSETS ($millions)	2005		2004		Change
Cash & Due  From  Banks	$873		$691		26.3	%
Trading Securities	24		47		-48.9
Short - Term  Investments	158		136		16.2
Investment  Securities	6,158		6,010		2.5
Loans and Leases:
Commercial  Loans & Leases	9,096		7,719		17.8
Commercial  Real  Estate	9,702		8,424		15.2
Residential  Real  Estate	5,041		3,375		49.4
Home Equity Loans & Lines	5,162		4,604		12.1
Personal  Loans and Leases	1,582		1,934		-18.2
Total  Loans and Leases	30,583		26,056		17.4
Reserve for Loan & Leases Losses	(358)		(354)		1.1
Premises and Equipment, net	445		434		2.5
Goodwill and Intangibles	2,152		1,104		94.9
Other  Assets	1,606		1,352		18.8
Total  Assets	$41,641		$35,476		17.4	%
LIABILITIES & SHAREHOLDERS' EQUITY ($millions)
Deposits:
Noninterest Bearing	$4,790		$4,360		9.9	%
Bank Issued Interest Bearing Activity	9,860		9,956		-1.0
Bank Issued Time	4,051		3,213		26.1
Total Bank Issued Deposits	18,701		17,529		6.7
Wholesale Deposits	7,001		5,622		24.5
Total  Deposits	25,702		23,151		11.0
Short - Term  Borrowings	4,456		4,619		-3.5
Long - Term  Borrowings	5,892		3,221		82.9
Other  Liabilities	1,569		1,083		44.9
Shareholders'  Equity	4,022		3,402		18.2
Total  Liabilities  &  Shareholders'  Equity	$41,641		$35,476		17.4	%
	Three Months Ended
	March 31,		March 31,		Percent
	2005		2004		Change
AVERAGE  ASSETS ($millions)
Cash & Due  From  Banks	$919		$771		19.2	%
Trading Securities	23		23		0.0
Short - Term  Investments	187		213		-12.2
Investment  Securities	6,101		5,680		7.4
Loans and Leases:
Commercial  Loans & Leases	8,858		7,541		17.5
Commercial  Real  Estate	9,516		8,321		14.4
Residential  Real  Estate	4,729		3,227		46.5
Home Equity Loans and Lines	5,131		4,438		15.6
Personal  Loans and Leases	1,650		1,901		-13.2
Total  Loans and Leases	29,884		25,428		17.5
Reserve  for  Loan  &  Leases  Losses	(361)		(356)		1.4
Premises and Equipment, net	451		438		3.0
Goodwill and Intangibles	2,142		1,108		93.3
Other  Assets	1,695		1,539		10.1
Total  Assets	$41,041		$34,844		17.8	%
Memo:
Average Earning Assets	$36,195		$31,344
Average Earning Assets Excluding Investment Securities
Unrealized Gains/Losses	$36,156		$31,261
AVG  LIABILITIES & SHAREHOLDERS' EQUITY ($millions)
Deposits:
Noninterest Bearing	$4,693		$4,316		8.7	%
Bank Issued Interest Bearing Activity	9,877		9,992		-1.2
Bank Issued Time	3,861		3,243		19.1
Total Bank Issued Deposits	18,431		17,551		5.0
Wholesale Deposits	6,803		4,964		37.0
Total  Deposits	25,234		22,515		12.1
Short - Term  Borrowings	2,893		3,428		-15.6
Long - Term  Borrowings	7,205		4,243		69.8
Other  Liabilities	1,729		1,284		34.7
Shareholders'  Equity	3,980		3,374		18.0
Total  Liabilities  &  Shareholders'  Equity	$41,041		$34,844		17.8	%
Memo:
Average Interest Bearing Liabilities	$30,639		$25,870
M&I  Corporation
Financial Information
(unaudited)
	Three Months Ended
	March 31,		March 31,		Percent
	2005		2004		Change
CREDIT  QUALITY (a)
Net Charge-Offs ($millions)	$8.0		$4.9		63.3	%
Net Charge-Offs / Average Loans & Leases	0.11	%	0.08	%
Loan and Lease Loss  Reserve ($millions)	$358.3		$353.7		1.3	%
Loan and Lease Loss  Reserve / Period-End  Loans & Leases	1.17	%	1.36	%
Non-Performing Loans & Leases (NPL) ($millions)	$130.0		$156.1		-16.7	%
NPL's / Period-End Loans & Leases	0.42	%	0.60	%
Loan and Lease Loss Reserve / Non-Performing Loans & Leases	276	%	227	%
MARGIN  ANALYSIS (b)
Loans and Leases:
Commercial  Loans & Leases	5.43	%	4.67	%
Commercial  Real  Estate	5.85		5.37
Residential  Real  Estate	5.71		5.56
Home Equity Loans and Lines	5.74		5.35
Personal  Loans and Leases	5.53		5.14
Total  Loans and Leases	5.67		5.17
Investment  Securities	5.01		5.01
Short - Term  Investments	2.73		1.08
Interest Income (FTE) / Avg. Interest Earning Assets	5.54	%	5.11	%
Interest Bearing Deposits:
Bank Issued Interest Bearing Activity	1.38	%	0.63	%
Bank Issued Time	2.74		2.38
Total Bank Issued Deposits	1.76		1.06
Wholesale Deposits	2.61		1.69
Total Interest Bearing Deposits	2.04		1.23
Short - Term  Borrowings	3.08		1.86
Long - Term  Borrowings	3.85		3.70
Interest Expense / Avg. Interest Bearing Liabilities	2.57	%	1.72	%
Net Interest Margin(FTE) / Avg. Earning Assets	3.36	%	3.69	%
Interest Spread (FTE)	2.97	%	3.39	%
Notes:   (a)   Includes Loans past due 90 days or more
(b)   Based on average balances excluding fair value adjustments for available for sale securities.