The European Community has accepted an accord with the United States to limit exports of Common Market steel tubes and pipes to 7.6 percent of the U.S. market, an EC Commission spokesman said today.

He said the proposal will now be presented to the Reagan administration. "We need official confirmation from the United States on the agreement," the official said. He added that further negotiations on the issue with the United States likely will not be necessary.

Meanwhile, the American Iron and Steel Institute reported today that U.S. imports of steel from Japan are running almost two-thirds higher than last year.

According to the institute's figures, Japanese exports of steel mill products to the United States reached 6.2 million tons for the first 11 months of 1984, compared with 3.7 million tons for the same period of 1983 -- an increase of 64 percent.

The institute said imports from all sources took 29.3 percent of the U.S. market in November, slightly less than the record level of 31.7 percent set in July. The Reagan administration has begun to make agreements with major suppliers, designed to help hold imports down to 18.5 percent of the market and reserve the rest of the business for Americans.

Japanese Prime Minister Yasuhiro Nakasone is due to meet President Reagan in Los Angeles next Wednesday but the two countries have yet to reach agreement on cutting future exports from Japan.

A last-minute snag over a French objection almost blocked the EC agreement.

France wanted assurances that the plan wouldn't prevent its producer, Vallourec, from supplying its product to a pipeline project in the United States. But France received the assurances it wanted and dropped its opposition, EC sources said.

France's acceptance of the pact means that a special ministerial meeting won't have to be held. Earlier, the commission was reported to have requested a council meeting to be held before the end of the year.

Under the proposed accord, the EC would limit exports of steel tube and pipe to 7.6 percent of the U.S. market in 1985. European producers would only be allowed to exceed the quota if there were a "short supply" of the product on the U.S. market.