House and Senate conferees agreed yesterday on legislation that would ease federal aircraft noise abatement standards for the smaller jet planes.

Under existing Federal Aviation Administration regulations, airlines are required to alter or replace two-engine and three-engine jets to meet the standards by Jan. 1, 1938. Four-engine jets must comply by Jan. 1, 1985.

The compromise measure, hammered out in six sessions including yesterday's all-day meeting, would:

Exempt from the 1983 standards entirely all two-engine jets. The 450 planes affected -- McDonnell Douglas DC9s, Boeing 737s and BAC-111s -- are owned mostly by regional airlines and are the jets used for small community services. Proponents of the waiver, including Senate Commerce Committee Chairman Howard W. Cannon (D-Nev.), contended that small towns would suffer a loss of air service if compelled to meet the standards -- either by replacing the planes with larger jets or by deciding to put the planes on the ground rather than go through the expensive process of altering them.

Allow airlines to continue using three-engine jets that do not meet the 1983 standards if they already had ordered quiet new planes to replace them. The new planes, which also use 30 percent less fuel, have to be delivered by Jan. 1, 1985.

Allow airlines that choose to replace engines on their Boeing 727 three-engine jets to meet the same noise standards now required of brand new 727 planes coming off the production line. Current regulations would have required the altered planes to be even quieter than the planes now being made.

The conferees also agreed on a measure that would assure that the pro-competitive international aviation policy of the current administration is future policy no matter who occupies the White House. The bill also would allow airlines the flexibility to raise or lower foreign fares within a certain zone without going to the Civil Aeronautics Board for approval. In addition, the measure would allow the CAB to grant foreign airlines the right to pick up domestic U.S. passengers during emergencies.

Attached to both measures is an amendment that would restrict interstate air services from Dallas' Love Field. The amendment, sponsored by House Majority Leader Jim Wright (D-Tex.), was agreed to by a "reluctant" Sen. Cannon, as he put it, after all parties to the Texas dispute agreed on a compromise.

The compromise would allow Southwest Airlines to continue its low-fare service out of Love Field into Louisiana and would allow it to expand interstate services into four states contiguous to Texas, but no more.

Wright's original plan was to eliminate even Southwest's current interstate service. Yesterday, Herbert D. Kellecher, the chairman of the board of Southwest, said he had agreed to the compromise "to bring peace." Although the measure definitely will constrain Southwest's future plans, he said it would end seven years of litigation over the airline's right to even operate from the airport and the "virulent form of hostility" between Dallas and Fort Worth over air services and their joint operation of a regional airport. It also means Southwest will concentrate more on interstate services from Houston, Kelleher said.

Although conference member Rep. Elliott Levitas (D-Ga.) said Transportation Secretary Neil Goldschmidt in a telephone conversation hinted that the president would veto the noise legislation, Cannon was optimistic that the president would sign it.

Noting that the administration had a number of bills pending, Cannon said, "I would hope they wouldn't be rash enough to say they would veto the noise bill until they find out a little more about it."