The White House yesterday came out swinging against the tentative outlines of a congressional budget compromise, even as House-Senate negotiators stalled short of agreement on crucial aspects of the plan, especially domestic spending.

One conferee said spending levels for Medicare, job training, defense, foreign aid and revenue-sharing were among the key obstacles to agreement as leaders of the two negotiating teams huddled privately in an unsuccessful attempt to pull together a proposal for submission to the full conference.

Just as the key negotiators were attempting to reach a final agreement, White House deputy press secretary Larry Speakes, who had been relatively mild in his criticism of the congressional efforts a day earlier, called the plan "out of line and off-base on every major segment of the budget."

Speakes said the president is "strongly opposed" to the compromise as it appears to be shaping up.

The White House opposition came as no surprise to the negotiators in light of President Reagan's displeasure with tax, defense and domestic spending proposals in budget drafts that had been approved earlier by both the Democratic House and the Republican Senate.

But it could add to the obstacles threatening passage of a budget compromise, especially in the Senate, and thereby complicate the delicate balancing efforts by negotiators to come up with a package that can attract a majority in both houses.

"It doesn't help anyone when the president starts throwing rocks at the process," House conferee Leon E. Panetta (D-Calif.) said. Not only do Republicans get jittery, but "Democrats get more combative," he said.

The conferees scheduled another meeting Monday, when they hope to complete work to avoid having to go back to both houses for reauthorization of the conference.

There was only glancing reference to the White House as budget negotiators reemerged briefly in public session after two days of private bargaining to announce that, despite attempts to finish yesterday, they still were at odds over major issues.

"We have made some headway," Senate Budget Committee Chairman Pete V. Domenici (R-N.M.) said. ". . . However, there are still significant differences. There's certainly a chance we will resolve them."

The conferees tentatively have agreed to tax increases of $72 billion over three years, starting with $12 billion next year, which Speakes described as "the wrong thing at the wrong time."

Although they have narrowed their differences over domestic spending, including agreement to set up a contingency fund for recession relief programs proposed by the House, they reportedly still have major differences over several issues, including proposed Senate retrenchments in Medicare. But they are agreed in rejecting most of Reagan's proposed program cuts.

On defense, they have agreed to a 5 percent after-inflation spending increase, half of what Reagan wants, but still are haggling over an estimated $2 billion difference in the amount. In any case, Speakes said, their proposal is "far, far below what the president thinks is necessary."

White House objections surfaced indirectly at the conference when Rep. Ed Bethune (R-Ark.), complaining that the conference isn't "sensitized" to Reagan's position, protested that the key negotiators were trying to keep their work "a secret" from the White House and House Republicans.

"None of the qualities you attribute to what we are trying to do is real," Domenici responded icily.