The Senate approved a $3.6 billion aid package for Chrysler Corp. yesterday, clearing the way for Congress to iron out House-Senate differences today and send the measure to President Carter.

Approval came in a late-night session after the Senate broke a logjam on the key issue of how large a wage concession to require from the United Auto Workers union as a condition of the aid. The final vote was 53 to 44.

The Senate-passed legislation would provide for $1.5 billion in federal loan guarantees for Chrysler, to be matched by $2.1 billion in loans or concessions from private parties -- workers, banks, states and suppliers -- involved in the rescue effort.

The Senate voted yesterday to require UAW members to forgo $525 million of an estimated $1.3 billion in wage increases in the next three years. By comparison, the House bill would require the union to give up $400 million.

The Senate rejected an amendment that would have allowed Chrysler to use $500 million in loan guarantees immediately to obtain interim financing until the conditions in the legislation are fully met.

However, this may not necessarily preclude Chrysler from obtaining an interim loan. Some lawmakers say the House bill would permit immediate use of the federal guarantees. The issue may be decided in conference today.

Approval of the Chrysler bill is the last major item on Congress' agenda this session. If a House-Senate conference can agree on a compromise this afternoon, the lawmakers could adjourn as early as tonight.

The House version of the loan guarantee bill would provide for the same $1.5 billion in federal backing, but would only require $1.9 billion in concessions and loans from private parties such as suppliers and banks.

The remaining differences between the two bills are relatively minor.

The Senate bill would require $150 million in salary concessions from Chrysler's white-collar employes, compared to $100 million in the House measure. The Senate bill calls for a three-member board to administer the loan; the House bill calls for a five-member board.

Both proposals would require Chrysler to give union workers significant amounts of company stock, in part to compensate them for their wage restraint and to give them a bigger stake in the firm's financial success. w

The Senate bill would transfer $175 million worth of stock to Chrysler employes -- about 30.9 percent of the estimate 60 million shares now outstanding. The House bill would give them $150 million in stock.

Yesterday's breakthrough on the wage concession followed a chaotic morning session in which the bill was almost derailed in a Senate backlash against liberals' efforts to cut back the wage increases that the union would have to give up.

The original Senate measure called for a wage freeze, effectively forcing the UAW to forgo $1.3 billion in raises. Under union prodding yesterday, the Senate first voted, 54 to 43, to limit the concession to $400 million.

However, opponents of the proposal rallied and threatened a filibuster that would have blocked the bill indefinitely. After some off-the-floor negotiations, the first vote was reversed and the Senate approved the $525 million concession requirement 69 to 28.

The filibuster threat was crucial because if the Chrysler bill does not pass this session, the company almost certainly will go bankrupt before the lawmakers resume work on the legislation in January.

Chrysler served notice last week that, because of a slump in auto sales, it now expects to run out of cash in January instead of February, as estimated earlier. Executives say they still will need an interim loan to carry on.

Proponents of the bill had argued that a failure by Chrysler would put 350,000 employes out of work -- 140,000 direct employes of the automaker and 210,000 workers at suppliers' plants and dealers' establishments.

The $525 million wage concession would require the UAW to give up $325 million in additional pay increases. In anticipation of a wage concession requirement, the union already agreed to forgo $200 million in raises.

Both the House and Senate versions of the bill would require these loans and contributions from the major parties in the rescue effort: $500 million from U.S. banks, $300 million from the sale of Chrysler assets, $250 million from state and local governments, $180 million from suppliers and dealers, $150 million from Canadian banks and $50 million from the sale of equities.