There is a reasonable chance that the U.S. Senate will agree to add two members from the District of Columbia when it considers a bill to grant congressional voting rights to the city, Sen. [WORD ILLEGIBLE] Bayh (D-Ind.) told a House hearing yesterday.

Bayh and Del. Walter F.Fauntroy (D-D.C.) testified as a Judiciary subcommittee opening hearings into the voting bill, which would give the city two members each in both the Senate and House while retaining the city's status as a federal district, not a state.

Fauntroy said passage of the bill by the House this year is "a reachable goal." To go into effect, the measure - an amendment to the Constitution - must be approved by 38 state legislatures.

Supporters of the measure had hoped that President Carter would send a message of support for the measure, but none arrived.

Rep. Don Edwards (D-Calif.), chairman of the Civil and Constitution Rights Subcommittee, said no statement was solicited from the White House, adding that future presidential support is vital to passage of the measure.

Soon after taking office last January, Carter endorsed voting representation in the House but left open the question of Senate voting.

Martha (Bunny) Mitchell, Carter's liaison on District matters, said the President soon will receive a recommendation on the issue from a task force considering District of Columbia issues. Until then, there is no change in his earlier position, Mitchell said.

Bayh, who is chairman of the Senate Judiciary subcommittee that would hold hearings on the voting measure once passed by the House was asked by Rep. Robert F. Driman (D-Mass.) to assess the measure's chances in the Senate.

It is regarded as vulnerable there since members of the Senate would have to agree to enlarge their numbers from 100 to 102 to bring it about.

"I think we have a reasonable chance of passage," Bayh replied. "I will make the best effort I know now . . .

Rep. M. Caldwell Butler (Va.), the House subcommittee's senior Republican, pointed to a related problem in the House: with House membership limited by law to 435 and unlikely to be expanded, the District's two House seats would be taken from other states.

Butler, who opposed D.C. voting representation the last time Congress considered the issue in 1975 and 1976, said he has shifted and now supports the city's bid for voting representation in the House.

Repeatedly, Butler speculated yesterday that the Senate would refuse to enlarge itself. He explained that he is "anxious to . . . get something that will pass."

Butler's fear of the Senate's opposition, Bayh replied, reflects "a sensitive area . . . a very selfish argument" by some members of the Senate that did not prevail when Alaska and Hawaii were admitted to the union in the 1960s.

Yesterday's hearing plowed no legal ground that was not covered at a similar series of hearings in 1975, and Edwards said much of the detailed testimony from that year will not be repeated. More hearings are expected in September.

As amended on the Housefloor, where it fell 21 votes short of passage in 1976, that year's measure would have given the District two representatives in the House and would have authorized the Senate to decide for itself whether the city should have two senators.

The measure now pending would give the city full voting representation in both houses - two senators and, based upon population, probably two representatives.

The new measure would do two other things. It would give the D.C. City Council the power to pass upon constitutional amendments, like the 50 state legislatures do now. It also would put the District on the same rooting as the states in casting votes for President through the Electoral College. That would give the city four electoral votes instead of the three now mandated by the 23rd Amendment to the Constitution.