White House and congressional negotiators are close to a budget compromise that would keep next year's deficit under $100 billion, but they need President Reagan's assent before they can go any further, Democratic and Republican congressional sources said yesterday.

The general framework for a compromise, worked out in three weeks of private negotiations, includes tax increases of about $30 billion for fiscal 1983, cuts in Reagan's proposed defense buildup and new limits on benefits in the large domestic entitlement programs, according to congressional sources.

Proposals under serious consideration would produce more than $400 billion in deficit reductions over the next three years, including more than $120 billion in tax increases, according to administration as well as congressional sources.

But final agreement, including nailing down details, awaits signals from the two principals in the budget struggle, Reagan and House Speaker Thomas P. (Tip) O'Neill Jr. (D-Mass.), neither of whom has participated directly in the talks and both of whom have expressed reservations about some of the proposals.

Yesterday the focus was on Reagan, whose cooperation is viewed as critical to bringing O'Neill along.

In a statement released before a news conference in Albuquerque, Senate Budget Committee Chairman Pete V. Domenici (R-N.M.) said the negotiators "are at a stage where the president himself will have to give us some idea of his judgment on our package."

Added Domenici:

"I am fairly optimistic at this point, if we can get both Speaker Tip O'Neill and the president on board. We have narrowed the differences significantly and, frankly, I believe that those of us who have been negotiating could reach agreement tomorrow.

"However, we recognize that no agreement on a package will pass both the Senate and House this year without the enthusiastic support of the president. I hope that we can show the president a package that will command his enthusiastic advocacy, and I believe we are making real strides in that direction."

An aide to House Budget Committee Chairman James R. Jones (D-Okla.) said Jones also believes Reagan must make a move before the talks can proceed.

O'Neill issued a statement asserting that, in addition, Reagan must lead the fight for approval of any budget changes, which the speaker said would be "strong medicine" for many voters to swallow.

Reagan will be out of the country until Sunday and has yet to do much more than commission his chief of staff, James A. Baker III, to talk to congressional leaders about possible compromise.

But Domenici and others appeared encouraged by a request from Reagan for a delay in the Senate Budget Committee's scheduled resumption of work Tuesday on an alternative budget. Domenici told reporters that he and Senate Majority Leader Howard H. Baker Jr. (R-Tenn.) agreed to the postponement.

Among the revenue-raising measures under consideration by the negotiators are a $5 a barrel oil import fee, a 4 percent income surtax that might be applied only to upper-income taxpayers and an excise tax on energy products other than home heating oil.

On the spending side, the negotiators are reportedly close to agreement on a delay and reduction in cost-of-living increases for Social Security and other big benefit programs. One proposal calls for a three-month delay and three-percentage-point reduction from what beneficiaries would otherwise get in inflation adjustments. The 1983 defense spending increase would be reduced from about 10 percent, after inflation, to roughly 7 percent, after inflation. Defense savings of $30 billion to $40 billion over three years are anticipated.

Senate sources said the goal from these and other proposals is a deficit of $85 billion for 1983, although House sources said a deficit of $100 billion is more likely. House Budget Chairman Jones has said a $180 billion deficit is likely without tax increases and spending cuts. The negotiators' goal for 1985 is a $50 billion deficit.

Meanwhile, a coalition of about 100 church, labor and civil rights groups announced a series of "nationwide grass roots activities" during the remainder of the congressional recess to protest the Reagan budget, including defense spending increases, social welfare cuts and what they called tax inequities.

"The glossing-over of people in the budget debate that promises some vague 'greater good' through the suffering of many is totally unacceptable," said Russell Sykes, field coordinator for the "Fair Budget Action Campaign."