Government officials are reviewing the trigger-price mechanism intended to protect the U.S. steel industry against unfair prices of imported steel but which recently has faced criticism from European officials, U.S. Trade Representative William E. Brock said yesterday.

Brock was asked during an interview following his trip last week to five Common Market countries whether the Reagan administration is planning to dismantle the trigger-price mechanism.

"Our view is that at the moment [the trigger price mechanism] offers us a better alternative than a whole series of protectionist cases," Brock said. "But we don't see it as a permanent or lasting solution."

Brock said that although the trigger-price mechanism is always under review, some European trade leaders met here last week with Commerce Department officials to see if some changes could be made in the system. brock said he does not know what changes are possible.

Some European government officials have complained lately that the trigger prices are being set too high. If a foreign company sells steel here at prices below the trigger, the government is supposed to conduct an antidumping investigation. The Europeans have said that their steel shipments here have been kept low because of the high trigger prices.

Brock said the slowdown in steel imports was not caused by the trigger prices, but by the depressed automobile market here, which uses the type of steel many european steel makers produce. In addition, imports of steel mill products reached their highest levels in 20 months in April, according to the Commerce Department, Figures for May are not yet available. The EEC was the largest source of imported steel during April, the Commerce Department added.

Brock siad he and government officials in Geneva, Brussels, Bonn, Paris and London did not discuss specifics about changes in the trigger-price mechanism. But he said he told some of the leaders that if they could produce steel fairly at prices below the triggers, they should apply for permission to sell steel here at lower prices.

Brock also said that he told European leaders who were complaining about high interest rates in the United State that such rates, while detrimental to the values of their currencies, provide an opportunity for the Europeans to increase sales and investment here.

"It's a significant opportunity to expand their sales in the U.S. markets," which could ameliorate the effects of high interest rates, Brock said.

The Europeans also were concerned over Japan's decision to limit voluntarily their shipments of cars to the United States.But Japan has assured them that cars originally intended for shipment here will not be diverted to industrialized nations, Brock said.

Many Europeans said that Japanese markets still are not sufficiently open, but he added that he does not know what the Europeans will do about it.

So far as trade relations with the new French government of Socialist President Francois Mitterrand are concerned, Brock said, any policy decisions have been put "on hold" until France's parliamentary elections are held in a few weeks.