Washington ? After months of bickering with the Bush administration over the price, House and Senate negotiators finally reached agreement Thursday on a $28.9 billion emergency spending bill to help pay for military operations in Afghanistan and other anti-terror initiatives.

The bill is expected to clear Congress and be sent to President Bush for his signature early next week, averting dire predictions of funding shortfalls at the Defense Department and Transportation Security Agency.

The compromise measure represents a big concession to the White House, which had threatened to veto earlier versions of the bill that would have cost more.

The long and often bitter effort to keep a check on spending pitted Office of Management and Budget Director Mitchell E. Daniels Jr. against Democrats and powerful members of Bush’s own party.

The retreat by lawmakers on the bill’s cost might strengthen the administration’s hand as Congress begins earnest work on the year’s 13 regular appropriations bills, which have shown signs of spiraling beyond Bush’s spending guidelines. Indeed, conservatives this week tied up House proceedings for two days to protest spending bills that they said would bust the budget.

The jockeying highlights the cross-pressures on Bush as he faces growing federal budget deficits. On one side, conservatives who are crucial to Bush’s political base argue that fiscal restraint remains their party’s stock in trade. But other Republicans are pushing the bounds of Bush’s budget request to improve GOP election prospects. In their view, budget discipline has been loosened by the economic downturn and demands of national security.

The emergency spending bill was this year’s first test of Bush’s ability to balance those conflicting forces. The compromise, drafted to resolve differences between House and Senate versions, includes $14.4 billion for the Pentagon, $6.7 billion for homeland security and $5.5 billion to help New York City recover from the Sept. 11 attacks.