The Senate, offering its alternative to the most controversial provision of a House-passed trade bill, yesterday voted 87 to 7 to require the president to file trade complaints against nations that "maintain a consistent pattern of import barriers."

The Senate provision, sponsored by Democratic leader Robert C. Byrd (W.Va.) and Republican leader Robert Dole (Kan.), would require the president to negotiate an end to such barriers by 1991 or impose some form of trade sanctions. As a third option, he could waive those requirements by saying that retaliation would be against the national interest.

The measure -- the last major provision of the Senate's trade bill, which will come up for final passage next week -- was crafted as an alternative to a provision in the House-passed bill pushed by Rep. Richard A. Gephardt (D-Mo.).

The Gephardt amendment, which critics have labled as protectionist, requires other countries to reduce their trade surpluses with the United States. President Reagan has said it will be vetoed if it remains in the bill that emerges from Congress.

The Senate sponsors went to great pains to differentiate their measure from the Gephardt provision. "What we have here is an alternative to Gephardt. It is not a son, a cousin or a stepchild, but a clear alternative," Dole said.

"The difference is protectionism versus reciprocity, market closing versus market opening," said Sen. John C. Danforth (R-Mo.), who worked with Sen. Donald W. Reigle (D-Mich.) in drafting the amendment.

Gephardt, though, said he "welcomed" the Senate action "as an encouraging step forward to ensure that American businesses, farmers and workers are given a chance to compete abroad."

But he expressed a number of reservations, including the absence in the Senate provision of specific targets for lowering trade surpluses of other countries that were gained through unfair trade practices.

Deputy U.S. Trade Representative Alan Woods said "we are strongly opposed" to the Senate amendment. "It could be veto bait if it isn't changed," he said.

But aides to the Senate Republican leadership noted that the administration "wasn't screaming" about the amendment and said they thought the president would eventually accept it.

The measure uses current trade laws as the stick that the president would be forced to use to bring an end to unfair trade barriers. But Danforth said it makes a critical change in trade policy by adding a systematic approach for identifying the major unfair practices that hurt U.S. overseas sales and by forcing the president to take action against them.

Dole noted that the president still has the flexibility to choose the actions he wants to take or to do nothing if he feels that is best.

The amendment requires the U.S. trade representative to institute trade complaints next March against countries that have been identified as having a "consistent pattern" of unfair ractices that hurt U.S. sales. These complaints would take as long as 19 months to process, and could result in the president ordering trade sanctions if the countries refuse to eliminate trade barriers.

At the same time, however, the amendments require the government to negotiate an end to those practices by March 1991. The trade complaints, with their threat of retaliation, would provide the impetus to push the negotiations forward.

The White House also is required to report to Congress each year on the pace of efforts to eliminate barriers to U.S. imports.

Although no country is mentioned in the legislation, Japan was singled out in the report on the bill and in the floor statements of a large number of senators. Reigle said the provisions would also apply to countries such as Taiwan and South Korea.

"This amendment marks a major breakthrough in stopping trade abuse that is hurting America, costing us millions of jobs and hurting U.S. business firms and industries," Reigle said.

"We are trying to get at unfair trade barriers to U.S. exports," added Danforth. "We are not trying to create some sort of trade balance and we are not trying to assure U.S. sales where we are not competitive."

Sen. Max Baucus (D-Mont.) said the legislation was an improvement over the Gephardt amendment but still could have been stronger.

"It's not going to do nearly what the proponents suggest," he said.

The measure was watered down during negotiations to achieve the broad bipartisan support in the Senate. Danforth, who played a leading role in the talks, noted that the amendment drew the support of 87 senators "representing very diverse viewpoints on trade."

He said the approach was neither "old-fashioned protectionism" nor makes the United States a "doormat" for countries that consistently use unfair trade tactics.

The opposition came entirely from the Republican side.

Voting against the amendment were Sens. Daniel J. Evans (Wash.), Phil Gramm (Tex.), Mark O. Hatfield (Ore.), Gordon J. Humphrey (N.H.), James A. McClure (Idaho), Steve Symms (Idaho) and Malcolm Wallop (Wyo.).