Henry Rosovsky, dean of the faculty of arts and sciences at Harvard University, has been offered the presidency of Yale, sources said yesterday.

Rosovsky, an economist and expert in Asian affairs, has not formally accepted the offer, sources cautioned, and is thought to be making up his mind on whether to take the job, one of the most prestigious posts in American higher education.

If he accepts, he would become the first Jew to serve as president of one of the Ivy League's "big three" - Harvard, Yale and Princeton.

The decision to offer the post to Rosovsky was apparently made at a meeting of the Yale Corp. last week in Washington. It ended one of the most secretive and extensive searches for a college president in recent times.

The Yale presidency became vacant last spring when Kingman Brewster, a controversial spokesman for campus liberalism in the 1960s, was appointed ambassador to the Court of St. James's.

The list of potential candidates to succeed him included some of the nation's most prestigious academicians and a bevy of influential Yale alumni, including former Pennsylvania Gov. William Scranton and former President Ford.

One of the most frequently mentioned candidates for the post. Yale's acting president Hanna Gray, accepted the presidency of the University of Chicago last week, apparently after waiting to find out if she would be the first woman offered the Yale job.

Yale officials last night would neither confirm nor deny reports of the appointment. Attempts to reach Rosovsky were unsuccessful.

Sources close to the Harvard dean, however, said the offer had been made and he is considering it. Cointacted at his home in Cambridge, Mass., Harvard President Derek C. Bok refused to comment on the selection, saying it would seriously damage an institution if reports were published that an individual had been offered the job and that individual subsequently refused to accept it.

If Rosovsky takes the job, it would be the second time in the last two decades that a top post at Harvard served as a stepping-stone to the presidercy of Yale.

Before he came to the New Haven, Conn. campus as provost. Brewster was a professor of law at Harvard.