Senate Budget Committee Chairman Pete V. Domenici (R-N.M.) said yesterday that he will confer with White House officials about a possible compromise on defense spending, but indicated doubt that the committee will reverse its decision of last week to cut the president's proposed military budget increase in half.

Asked if a compromise is possible, Domenici said, "I haven't ruled it out, but I do not know at this point how it can be done."

He added, "We are talking . . . . There's some discussion but not any numbers."

Any new negotiations probably will be with White House chief of staff James A. Baker III instead of Defense Secretary Caspar W. Weinberger.

Baker is seen as a pragmatist, while Weinberger has been widely blamed for bringing on last week's rebuff through intransigence. But some Republicans as well as Democrats were saying it probably is too late.

"They've been intransigent so long" that "they've hurt the consensus on defense," said Sen. Lawton Chiles (D-Fla.), ranking Democrat on the committee.

Chiles said he can count at least four Republicans who would join all committee Democrats in balking at anything more than the approved growth in defense spending 5 percent above inflation--half what the administration wants. Moreover, he said, he doubts that the full Senate would approve 7 percent, which had once been considered as a possible compromise.

The 5 percent figure is a somewhat fluid one, however, and it could slide up or down depending both on future actions by the committee and on methods that are used to compute it.

Budget Committee aides said yesterday the figure would be closer to 5.4 percent if the committee used the administration's formula for calculating inflation, and some outside sources have said it actually would be more than 6 percent.

However, the committee has yet to decide on whether to recommend giving government workers, including the military, a pay raise. If it follows the House and allows room for a pay raise, which the administration doesn't want, the extra pay would be computed as part of inflation costs for the Pentagon, thereby reducing the "real," or after-inflation, increase that could be claimed for defense.

It was inclusion of a military pay raise by the House in its defense share of the budget that caused Reagan to assert that the "real" defense increase voted last month by the Democratic House was closer to 2.3 percent than the 4 percent claimed by Democratic leaders.

Although the issue is largely a bookkeeping one, a "real" defense increase of less than 5 percent from the Republican-controlled Senate would compound the extent of Reagan's defeat in a symbolic sense.

While predicting that the committee will hold the line on defense, Chiles, in a luncheon with reporters, indicated little hope that the Democrats, in league with some Republican moderates, will succeed in one of their main goals: repeal of the 10 percent tax cut scheduled for July 1.

But he said the push for repeal increases leverage for revenue increases to help reduce Reagan's projected 1984 deficit of $189 billion without resorting to heavy cuts in domestic spending.

The Democrats' goal is "as much as we can get--up to $30 billion," but "at least $15 billion," Chiles said. The House has approved a tax increase target of $30 billion that assumes both repeal of the July tax cut and cancellation of tax indexing for inflation in the future.

Chiles and other Democrats made clear that they will demand flexibility from the Republicans on taxes as a price for at least some Democratic support in containing the burdgeoning costs of many benefit entitlement programs.

But Chiles indicated that entitlement cost-cutting is not likely to extend beyond curbs on cost-of-living increases similar to those already approved for Social Security.