The Senate, ending a deadlock on trade and deficit cuts, agreed yesterday to resume floor action next week on proposed rollbacks in textile and apparel imports.

"I think this breaks the logjam," Senate Majority Leader Robert J. Dole (R-Kan.) said as the Senate approved the compromise plan, which would detach the textile issue temporarily from an $85.6 billion deficit-cutting package. When the two measures became entangled two weeks ago, action on both came to a standstill.

Meanwhile, a House Banking subcommittee yesterday unanimously approved President Reagan's proposal for a $300 million "war chest" with which to subsidize American exports.

The Senate textile bill, advancing under the long-standing threat of a presidential veto, is the leading edge of a wave of anti-import legislation. It would order major cutbacks in cloth and apparel shipments from Taiwan, South Korea and Hong Kong, and impose lesser curbs on those from other nations.

Under Dole's plan, the Senate will take up a House-passed version of the textile bill on Wednesday and immediately choke off debate.

Earlier, Sen. Dan Evans (R-Wash.) indicated he will try to defeat the bill with an array of amendments. Evans met with President Reagan yesterday and said he was "absolutely convinced" a veto awaits the textile bill if it passes.

The export subsidy proposal is designed to encourage sales abroad and reduce the United States' trade deficit, which is expected to reach $150 billion this year.

The bill would set up a fund in the Treasury Department for grants to foreign buyers of American goods. The approved measure is expected to go to the full committee before the Christmas recess.

"The money would not actually leave the United States if Congress enacts the plan as proposed by the president," said Russ Boner, a spokesman for the government's Export-Import Bank. "It would go to the American supplier as part payment for the goods."

On another front, and in a rare show of unanimity, all 47 Senate Democrats yesterday joined as cosponsors of a five-point trade bill that would give the president negotiating authority for a new round of world trade talks.

The bill would also create a new White House agency, the National Trade Council, to give the issue increased status in the upper levels of the executive branch. The National Trade Council would be on the same level as the National Security Council.

The bill was introduced by Sen. Lloyd Bentsen (D-Tex.), chairman of the Senate Working Group on Trade Policy, on behalf of all of his colleagues.