Maryland Acting Gov. Blair Lee, III replaced his son as manager of his gubernatorial campaign yesterday, hiring a more seasoned political hand to direct his race four weeks before the Democratic primary.

The new campaign manager is Joseph G. Anastasi, who ran as a candidate for lieutenant governor on the ticket of Attorney General Francis (Bill) Burch until he withdrew his candidacy for governor last month.

The acting governor's son, Blair Lee IV, who encouraged Anastasi to take the job in a series of recent meetings, will continue as deputy campaign manager in charge of fund raising and mass media advertising.

"I never considered myself more than a novice," said the younger Lee, who is known as "B-IV." "This wasn't the position I sought in the first place. Joe will give us the experience we've been lacking."

Lee campaign sources say the acting governor's son has left the campaign staff rudderless in recent weeks as he concentrated on raising funds for his father's testimonial in Baltimore Tuesday.

According to sources, the younger Lee had difficulty delegating responsibility to other campaign workers and did not get along well with Fran Tracy, the deputy campaign manager in charge of scheduling.

"It was a question of miscasting," explained one source. "B-IV was good at fund raising. Fran is very good at scheduling. Neither of them was very good at the master plan. That's where Joe comes in."

Anastasi, a Montgomery County resident, managed Gov. Marvin Mandel's first gubernatorial race in 1970 and the 1963 presidential campign in maryland of the late Hubert H. Humphrey.

He served as Maryland secretary of Economic and Community Development under Mandel and Lee, resigning last year after he and Lee feuded over a gloomy Anastasi report on the state's economy.

Anastasi said he joins Lee at a time when "everthing's in good shape. The campaign isn't sagging any more than any other campaign. When you get to this point, everybody gets a little bit panic-striken."

The younger Lee, who was enlisted a year ago to run his father's campaign said he is "tickled pink" that Anastasi decided to join the campaign. "There's more work than we have people at the top," he said.

"It's not going to change my life a bit," Blair Lee IV said. "I'm still signing checks and working on the media. I'll get more sleep knowing that the things not getting done (before) will be getting done."