The Soviet Union and West Germany, concluding two days of high-level commercial talks, complained today that American-backed restrictions on the flow of technology were hampering prospects for improved East-West trade.

Leading members of both delegations contended that a qualitative jump in trade between the Soviet Union and Western countries could bolster East-West political dialogue. But they warned that such an improvement was not likely unless Western trade limits on high-technology items were eased.

The trade talks between the Soviet Union and West Germany, its biggest trading partner in the West, appeared to confirm a willingness by Moscow to pursue renewed economic as well as political initiatives with the West. Similar U.S.-Soviet talks, the first in six years, took place in Moscow two weeks ago just as the superpowers agreed in Geneva to relaunch arms control negotiations.

Soviet Deputy Premier Alexei Antonov, who met with Chancellor Helmut Kohl and Foreign Minister Hans-Dietrich Genscher, said that increased economic contacts between East and West would contribute to a better political dialogue. "The Soviet leadership gave our delegation a mandate to make every effort to improve relations," he said.

Antonov and West German Economics Minister Martin Bangemann told a news conference that despite political strains over the past year, trade between their countries continued to grow beyond the $7.3 billion in two-way exchanges registered in 1983.

Moscow's next five-year plan, beginning in 1986, offered possibilities for more than $6 billion in new business contracts, they said, with the Soviet Union particularly interested in acquiring machine tools and chemical plants.

But Antonov stressed that the West's limits on high-technology exports to the Soviet Bloc could curtail such deals. "If the obstacles can be removed, the pace of trade will probably increase," he said.

The United States, Japan and the European allies have agreed to restrict the flow of sensitive goods and information to the East Bloc through a list of prohibited exports devised by the Paris-based Coordinating Committee representing the 15 participating nations.

But West Germany and other European countries have increasingly criticized U.S. efforts to expand the export ban to a degree that East-West industrial trade would be significantly affected. The Europeans say the United States profits unfairly because much of its economic dealings with the Soviet Union involve unrestricted agricultural trade.

Otto Wolff von Amerongen, the president of West Germany's chamber of industry and commerce, who participated in today's talks, said in an interview with a Soviet economic journal that it was becoming difficult to distinguish between military and civilian goods in the realm of "progressive technology."

Von Amerongen said industrial trade should not be restrained because technology does not observe borders. He indicated that unless some liberalization of the West's export ban took place, a substantial improvement in economic cooperation with the Soviet Union could not be expected.

Bangemann said today that the West German government would seek to expedite trade in borderline cases that faced potential difficulties because of narrow interpretations over the transfer of technology.

Kohl's center-right ruling coalition is eager to exploit West Germany's economic clout to repair relations with Moscow. Those ties have been damaged by tensions in the past year over the buildup of medium-range missiles in Europe and Soviet charges that Bonn hopes to incorporate East European territories lost during the war in a reunified German nation.

A more friendly dialogue with Moscow is considered a top foreign policy priority in Bonn because it is perceived as the key to closer relations with East Germany and other East bloc states.

At the same time, Kohl has averted a clash with Washington over the need to expand East-West commerce by loosening trade restrictions. He appears reluctant to become entangled in a row that could harm his working relationship with President Reagan.

Bangemann said he was optimistic that new projects hold out promise for a major expansion of economic links. He proposed that West German industry take part in the exploration and development of oil and gas fields in Soviet areas such as the Barents Sea and Sakhalin Island in the Far East.

In the past, Soviet-West German trade has been dominated by massive construction projects. West Germany was the main Western partner in building the Siberian gas pipeline that began pumping large amounts of Soviet gas to Western Europe last October. U.S. efforts to block European participation in the pipeline deal created serious friction within the alliance.

Bangemann contended that a better balance in trade could be struck by involving small- and medium-sized German companies in business deals. Bonn has traditionally run a big surplus in trade with the Soviet Union, but the trend shifted in 1983, and a German deficit surpassing $1 billion is expected to be announced for 1984.

Antonov endorsed the idea of expanding trade to include smaller firms if such efforts met the "necessary condition" of mutual gain. But he stressed that current restrictions presented serious problems because it remained unclear whether German companies would be able to fulfill orders subject to an eventual veto on strategic grounds.