Sen. Lloyd Bentsen (D-Tex.) warned yesterday that bipartisan Senate trade bills are more restrictive than a House-passed measure the Reagan administration opposes as partisan and protectionist. He called on the White House to work with Congress to draft legislation both houses of Congress can accept.

Otherwise, Bentsen said, President Reagan is likely to be faced with having to veto a trade bill in the middle of this fall's political campaign.

"If he vetoes it before Congress adjourns, I wouldn't be at all surprised to see Congress override him," continued Bentsen, the second-ranking Democrat on the Senate Finance Committee.

Even with administration participation, he said, it is "a close call" whether Congress will be able to agree on a trade bill this year. The House passed its bill last month, and momentum appears to be building for a Senate bill. But trade hearings will not be completed by the Senate Finance Committee's trade panel until the end of July, and it remains unclear whether the Senate can pass a bill in time to reconcile differences between the two versions before Congress adjourns.

Nonetheless, Bentsen said he is concerned that the administration is pressing for a new round of international trade talks without knowing what Congress or the American people want from them.

He said four years of record deficits will make trade "a serious political issue" in the November congressional election whether Reagan likes it or not. He noted that leading economists blame the trade deficit for a slowdown in the growth of the economy.

Bentsen made his remarks at a news conference during which he released a report by the Library of Congress' Legislative Reference Service that showed that six major Senate trade proposals, introduced by Republicans and Democrats, go further in limiting presidential discretion in trade matters than a bill passed last month by the House.

The administration has taken a hands-off approach toward trade legislation out of concern it would be faced with a bill it helped draft, but which contains provisions that are either too protectionist or too restrictive for Reagan to support.