WASHINGTON —  The Bush administration wants a big increase in spending for missile defense (search) next year, according to Pentagon budget documents.

Overall, the military plans to spend less next year to buy new weapons systems and more to maintain and upgrade helicopters, tanks and airplanes worn down by heavy duty in Iraq and Afghanistan. The total procurement budget request is $74.9 billion, compared with $81.1 billion for 2004, according to documents that were released by mistake Friday.

The request for the Missile Defense Agency (search) is $9.14 billion, according to a copy of the budget President Bush plans to send to Congress on Monday. That would be nearly 20 percent above last year's $7.6 billion for the agency.

The money is part of a total Defense Department budget request of $401.7 billion that includes an increase in spending on personnel alongside the decrease in overall spending on weapons for the budget year that begins Oct. 1.

The total military budget — 7 percent more than last year's $375.3 billion — does not include money for ongoing operations in Iraq and Afghanistan. The department got an $87 billion supplemental appropriation for those operations last fall and is expected to ask for another multibillion-dollar supplement later this year.

Details of the budget, normally closely held until the president sends his request to Capitol Hill, were inadvertently posted briefly on the Internet, and then withdrawn, defense officials said Friday.

The administration says the United States needs to develop missile defenses to guard against rogue nations such as North Korea that could fire missiles loaded with nuclear, chemical or biological warheads. Critics say the missile defense plan is too costly and relies on unproven technology.

According to the Pentagon documents, the overall military budget proposal will include a decline for buying aircraft — from $2.1 billion to $1.8 billion.

The Pentagon will, however, request an increase for the MC-130H Combat Talon (search) planes that are used to ferry special operations troops in and out of missions: $82.1 million compared with $8.8 million this year.

The proposal also includes more money for spare parts for Army vehicles such as tanks, armored personnel carriers and Humvees: $20.1 million instead of $17.9 million. Soldiers have complained that using the vehicles so heavily in the harsh environment of Iraq has caused them to break down more frequently.

There is also a slight increase for ammunition.

Personnel needs, including salaries and benefits, were put at $105 billion, up from $98.3 billion this year.

The Pentagon request is part of an overall $2.3 trillion budget that Bush will propose.