A Soviet official said Wednesday that the Soviet Union hopes to sign as many as five more commercial space deals with Western companies this year, similar to one announced last week with a U.S. company.

The official, Igor Alekseyev, declined to disclose details of any other deals, except to say that they would be mainly with West European countries, especially West German.Mr. Alekseyev, who heads the department responsible for the commercializatio n of space at the Soviet Foreign Licensing Office, Licensintorg, was attending an international space-commerce exhibition in Switzerland.

He told the Associated Press that the deal announced Feb. 18 between the Soviet Union and U.S.-based Payload Systems Co. was a small example of international cooperation on a commercial basis.

Under the deal, Payload Systems will perform a series of experiments aboard the Soviet space station Mir beginning in 1989. The experiments will be performed on behalf of unidentified companies, some of them in pharmaceuticals.

Payload Systems said in a release announcing the deal that the results of these experiments could contribute to the creation of new products by U.S. pharmaceutical, biotechnology and chemical companies.

Mr. Alekseyev said we hope this year that we will have some more contracts. It is quite a real possibility that we will have up to five, he said.

The Payload deal represented the first commercial space contract between a U.S. company and the Soviet Union. A West German company, Kayser Threde, signed a contract in December to launch a payload in an unmanned Soviet capsule.

The managing director of Payload Systems, George Economy, said his company chose to deal with the Soviet Union because it currently has the only space station in orbit permitting long-term experiments. He declined to provide any details of the deal.

We went to the Soviet Union because they can provide a service which is currently unavailable in the United States, said Mr. Economy, who was also participating in the conference.

But, he said: We've worked closely with NASA in the past and will continue to do so in the future. He said his company already has plans to perform experiments on future flights of the U.S. space shuttle.

The United States is jointly developing a space station with 11 other countries, but it is not expected to be in orbit before the mid-1990s. Meanwhile, private industry is working on an orbital research and manufacturing facility which could also be used for long-term experiments.

An official of the U.S. Commerce Department, Gregg Fawkes, said such a commercially developed system could be ready as early as 1991 and no later than 1993.

He said space experimentation is still in the early stages, and many companies who may eventually want to exploit it will not be ready to do so until then. Mr. Fawkes and other U.S. officials interviewed at the same conference said they did not expect many more U.S. companies to sign commercial space deals with the Soviets.

In my opinion, this is probably going to be a unique case, said James Rose, assistant administrator of NASA commercial programs.