President Carter sent Congress a draft Trade Agreements Act of 1979 yesterday which would revise domestic law to conform with multilateral agreements that were signed in Geneva on April 12.

Carter said that the new act would result in "a fairer, more open world trading system," and in the long run would mean lower inflation rates and a more favorable balance of trade for the United States.

The new trade act would implement the Geneva agreements, reducing tariffs modestly across the board, and for the first time introducing a series of seven international codes designed to eliminate or weaken non-tariff barriers to free trade.

At a White House press briefing, Special Trade Representative Robert S. Strauss - the chief American negotiator - labeled the package "the most significant trade negotiation ever conducted on befhalf of this nation."

He said it would benefit "every sector and region of our economy," adding that "it represents the very best (result) of the American political process in action."

Strauss said "there is no significant opposition" in Congress to the new trade act, which under the terms of the 1974 Trade Act can't be amended. Nevertheless, Strauss said he would stay on as STR until the legislation moves through both houses. he then will resign to assume his new post as the president's special ambassador for Middle East negotiations.

Strauss said he expects to be in the Middle East from June 30 to July 9, returning in time to testify on July 10 when the Senate Finance Committee takes up the trade treaty and a proposed trade reorganization bill.

He acknowledged that European nations and the group of poor countries were still far apart on a "safeguard" code, to restrain unilateral efforts by rich countries to exclude imports which have an overwhelming impact on the importing nation's economy. He also conceded that he had not been able to negotiate a wheat agreement. "But we decided we'd take no agreement, rather than a bum agretment," Strauss said.