An attempt by supporters of Ronald Reagan to stiffen the Republican National Committee's position on the Panama Canal treaties was dropped without a fight yesterday when it became obvious to the conservatives that their strategy would fail.

Instead, one Reagan backer rose at the conclusion of the party's winter meeting to offer a mild "expression of concern" over whether Republican Chairman Bill Brock still supports the thrust of an anti-treaty resolution adopted by the committee at an Oct. 1 meeting in New Orleans.

Almost perfunctorily, Brock told Texas Republican Chairman Ray Barnhart.Reagan's campaign manager in Texas in 1976, that he continues to support the New Orleans resolution.

It condemned the treaties "as proposed" by President Carter, but left the door open to a shift in case the pacts are modified along the lines suggested by Senate Minority Leader Howard H. Baker Jr. (R-Tenn.), a presidential aspirant.

Barnhart - along with the remainder of the Texas delegation. Committeeman John P. East of North Carolina, State Chairman Gordon M. Nelson of Massachusetts and several other members - had prepared a strongly worded resolution that, in effect, demanded U.S. soverignty over the Canal Zone, committee sources said.

The conservative group also considered presenting resolutions designed to pressure the national committee into using funds raised by the party, particularly those raised with the help of Reagan, for efforts to defeat the treaties. However, none of the resolutions surfaced.

"It's quite obvious we could not present a resolution in this atmosphere," Barnhart said after adjournment.

Only minutes earlier, a move supported by Reagan backers to make it easier for resolutions to be offered and debated at national committee meetings was crushed, 75 to 59.

Subsequently, the committee overwhelmingly passed by voice vote a measure requiring a two-thirds vote and 30 days' prior notice for the consideration of any resolutions at the national party meetings.

Conservatives on the committee, who were joined by a number of liberals and younger members, had argued vigorously for more than an hour that the measure amounts to a "gag rule" that will stofile minority views.

Comitteeman Ernest Angelo Jr., another Texas Reagan supporter, said he was "stunned" by the party headquarter's attempt to control resolutions, adding. "It makes it almost impossible for minority positions to get to the floor." He and other conservatives attempted to dilute the measure with amendments, but they were consistently defeated.

Committeeman William H. Stanhagen of Virginia argued that since his state's Republican committee had eased restrictions on debate of minority positions, the party's candidates have fared better than ever in elections. "What you're proposing is that we go backward," he said.

However, as the debate dragged on, Brock defended the resolutions restrictions, saying they would streamline meetings and make party business more orderly."The best evidence of that is what's going on right now: this meeting was supposed to adjourn at noon," Brock told a reporter as the clock approached 1 p.m.

The conservatives' defeat on the canal issue and the so-called "gag rule" came on the heels of a lopside 118-to-37 committee vote Friday to re-elect GOP Cochairman Mary Crisp. Brock was re-elected unanimously.

Reagan backers had sought to replace Crisp, who had been openly critical of the advocacy of "ideological purity" by conservatives.