The Carter administration, in a decision with political and economic significance for relations with the Soviet Union, has decided to allow the sale to that country of a large plant for producing oil well drilling bits.

The $144 million deal worked out by Dresser Industries, a Dallas firm, was the subject of widespread speculation and a new round of government policymaking when President Carter ordered reprisal actions last month for the political trials of dissidents Anatoly Scharansky and Alexander Ginzburg.

At that time Carter canceled the sale of a computer ordered by Tass news agency and decided to ban most travel to the Soviet Union of policy-level U.S. officials. Carter also announced that future exports of oil technology to Russia would be placed under a high-level review.

Most of the Dresser sale had been previously approved, but a

million segment to provide a sophisticated eletron-beam welding machine was subjected to study under the president's order. This machine contains a computer of its own.

According to Deputy Assistant Secretary of Commerce Stanley Marcus, the decision was made yesterday to approve the export license for the welding machine, which will permit the entire Dresser deal to go forward.

White House officials said Carter had decided to allow the case to be decided on its bureaucratic and technical merits, without regard for the state of U.S. Soviet political relations.

The effect of the decision is to limit, at least for now. U.S! economic reprisals for the dissident trials to the single case of the Tass computer.

There had been a sharp division of opinion within the administration about such actions, with Secretary of State Cirus R. Vance and Secretary of Commerce Juanita Kreps opposing the use of trade as political leverage, and presidential assistant Zbigniew Brzazinski and some of his National Security Council staff on the other side.

Ten days ago Vance informed the Commerce Department, which is charged with processing of export licenses, that he favored moving ahead with the sale of the oil drill plant.

Several senators, including Henry M. Jackson (D-Wash.). had called for cancelation of the Dresser oil deal, Jackson expressed regret last night that the final element of the arrangement has been approved, and said his permanent subcommittee on investigations will look into the matter.

He said providing such sophisticated technology is a poor idea at a time when the United States is attempting to persuade the Soviet Union to "live up to its commitments" on human rights.

Advocates and critics of the Dresser deal agreed that it would enhance the Soviet Union's ability to exploit its potentially vast oil resources.

Proponents of the sale said, among other things, that it is in the United States' interest that Russia be relatively self-sufficient in petroleum rather than be forced to draw large amounts of oil from the tight international market expected in the 1980s.