Baseball's powers that be have launched an investigation that puts George Steinbrenner, the shipbuilder with an affinity for landing in hot water, awash in a new sea of troubles.

Commissioner Bowie Kuhn's office and the American League say they will look closely into New York Yankee owner Steinbrenner's remarks last week about the Toronto pitching rotation and issue a joint judgement in response to the Blue Jay complaint that Stormin' George had cast aspersion on the intergrity of their management.

Peter Bavasi, Blue Jay president, demanded an apology from Steinbrenner after learning that the Yankee boss, in a conversation with AL President Lee MacPhail, had complained that Toronto was not starting a strong pitcher in the opener of its four-game series against Baltimore while the Yanks were battling Boston.

"He was accusing us of throwing a game," Bavasi snapped yesterday in declaring he was not content to let the matter die until "there is some kind of acknowledgement that owners of one club should not be meddling in the affairs of others."

Funny thing, the hurler Steinbrenner was maligning was southpaw Paul Mirabella, a man he thought enough of to make a Yankee in the 1978 deal sending Sparky Lyle to Texas -- and to package as bona fide goods in the big swap last winter with Toronto.

At any rate, the Blue Jays won two of four from the Orioles, reaching 61 wins for a club record as they headed into Yankee Stadium last night . . . with Steinbrenner maintaining he had not meant to suggest Toronto was playing favorites . . .

And with, as yet, no apology.