The Obama administration has given the Pentagon a $527 billion limit, excluding war costs, for its fiscal 2010 defense budget, an official with the White House’s Office of Management and Budget said Monday.

If enacted, that would be an 8 percent increase from the $487.7 billion allocated for fiscal 2009, and it would match what the Bush administration estimated last year for the Pentagon in fiscal 2010. But it sets up a potential conflict between the new administration and the Defense Department’s entrenched bureaucracy, which has remained largely intact through the presidential transition.

Some Pentagon officials and congressional conservatives are already trying to portray the OMB number as a cut by comparing it to a $584 billion draft fiscal 2010 budget request compiled last fall by the Joint Chiefs of Staff.

The $527 billion figure is “what the Bush people thought was the right number last February and that’s the number we’re going with,” said the OMB official, who declined to be identified. “The Joint Chiefs did that to lay down a marker for the incoming administration that was unrealistic. It’s more of a wish list than anything else.”

Defense budget experts have said the draft by the Joint Chiefs, which was never publicly released, was designed to pressure the Obama administration to drastically increase defense spending or be forced to defend a reluctance to do so. Defense officials in past outgoing administrations have left inflated budget estimates for incoming officials in the hope of raising the spending baseline. In fact, the draft budget was never scrubbed by Bush’s OMB, which had told federal agencies to submit draft budgets based on “current services.”

The Pentagon refused to comment publicly on why it would need the higher amount. Defense Secretary Robert M. Gates has said the fiscal 2010 defense budget must contend with the realities of the bad economy and stop the trend of steeply increases in military budgets since the Sept. 11, 2001, terrorist attacks.