The FBI, as part of its probe of Pentagon dealings, and the Securities and Exchange Commission are investigating the competition between two groups for a Navy blimp contract, The New York Times reported Monday.

In 1986, the Navy decided to develop a model blimp that could be used for radar surveillance, sparking feverish competition between the Goodyear Aerospace Corp., a unit of the Goodyear Tire and Rubber Co., and a joint venture of the Westinghouse Electric Corp. and Airship Industries, a British blimp maker.The two military contractors envisioned a potential $5 billion project involving 48 airships, the Times said.

The competition is now a subject of the FBI inquiry into alleged Pentagon bribery and fraud in awarding military contracts, according to pres-ent and former executives of the companies, federal investigators and others familiar with the case.

It also is being examined by a separate SEC investigation looking at whether information leaks from the Navy affected trading in the stock of Airship Industries, the executives and investigators told the Times.

The $168.9 million airship prototype contract was awarded to Westinghouse-Airship in June 1987.

Information suggests the FBI is looking at the airship consultants used by the Loral Corp., which acquired Goodyear Aerospace during the competition, the Times said. The information also suggests the SEC is looking at whether Navy leaks affected trading in Airship stock before the winning bid was announced, it said.

The price of Airship stock, which trades over the counter in the United States, soared to $31 from $16 in the weeks before the contract award was announced, the report said.

The stock is currently trading near $4, reflecting financing troubles for the airship after the Navy terminated the project earlier this year and passed it on to another Pentagon branch.

Goodyear Aerospace retained at least two Washington-area consultants who have figured in the Pentagon fraud inquiry, William M. Galvin and William Parkin, aerospace executives familiar with the program, told the Times.