O. Roy Chalk has chartered a new airline corporation and hopes to get back into the business of flying passengers between Puerto Rico and the American mainland.

Chalk, the colorful and often controversial former chairman and president of Trans Caribbean Airways and of the D.C. Transit System, announced his plans yesterday in a news release issued at his headquarters in sn old Georgetown car barn.

His motivation, he said, was the Civil-Aeronautics Board's decision on March 23 to investigate whether any more service is needed between several cities on the mainland, including Washington and New York, and Puerto Rico and the Virgin Islands.

Chalk's Trans Caribbean Airways - which he formed after World War II using surplus military aircraft, once flew such routes. In 1971, his company was merged into American Airlines, which abanoned the Trans Caribbean name, Chalk said.

The deal with American did not restrict him from going back into the airline business, Chalk said.

His new company is called Trans Caribair, Inc., and is chartered in Delaware. He said it is not a public corporation and is not affiliated with other Chalk-controlled enterprises.

Although the competition for any CAB certificate is expected to be brisk, Chalk predicted that he would have an inside track because of his experience and reputation.

"I intend to be a specialist in the ethnic and low-cost tourist market which isn't being exploited," Chalk told a reporter.

If he wins the certificate, Chalk said he plans to operate a one-class service using European-made airbuses. "The French government will do a substantial amount of the financing on the equipment," Chalk said.

D.C. Transit, Chalk's main Washington enterprise, sold its bus operations to Metro in 1973, but still has substantial real estate holdings here. Chalk also controls a Spanish-language daily newspaper in New York City.