Charles Pittman, Maryland's starting center, will undergo surgery this morning to repair the bone in his left foot fractured during practice Tuesday evening. He will be unable to play at least three weeks, by which time the regular season will have ended.

While Pittman, a 6-foot-8 senior, remained here, his team was in Chapel Hill, N.C., for tonight's 8 o'clock game against No. 2-ranked North Carolina (WMAL-TV-7). Pittman fractured the fifth metatarsal in his left foot after coming down with a rebound in a tangle of players during a scrimmage in Cole Field House.

Stanford Lavine, the team physician, will perform the operation, probably at Sibley Hospital, to insert a screw into Pittman's foot to facilitate healing. Maryland officials said Lavine told Pittman that he may be able to play again by March 5, the day the Atlantic Coast Conference Tournament begins in Greensboro, N.C. Lavine and Pittman were not available for comment yesterday.

Pittman's injury was a severe blow to Maryland's hopes of moving up in the ACC standings or gaining a bid to a postseason tournament.

Maryland (14-7, 4-5 in the ACC) has won three straight and Coach Lefty Driesell had talked confidently about his team's chances of beating the Tar Heels (18-2, 7-2), even though Carolina defeated Maryland, 66-50, in College Park earlier this season.

Pittman's aggressive offense has been a major factor in that improvement. In the last three games, he has averaged 17 points and 10 rebounds. He has started every game this season, is the team's second leading scorer (12.4), second leading rebounder (7.5) and is shooting 68 percent.

"Pittman has been playing great," Driesell said yesterday. "The best he's ever played here. This is something we'll just have to live with."

Driesell said he probably would replace Pittman with 6-11 Taylor Baldwin, who has started only one game this season, was averaging 2.3 points and 2.4 rebounds and playing fewer than nine minutes a game. Baldwin started the first eight games last season, while Buck Williams, now of the New Jersey Nets, was recovering from a broken hand.

But Baldwin will not have the supporting cast tonight that he had last season. He must get rebounding help from forwards Herman Veal (Maryland's top rebounder), Mark Fothergill and Adrian Branch if the Terrapins are to be competitive with North Carolina's Sam Perkins and James Worthy.

Perkins scored 23 points and had eight rebounds in the first game against Maryland, while Pittman and Baldwin together got only nine points and nine rebounds. Even with Pittman playing, Maryland would have been a heavy underdog in Carmichael Auditorium.

Driesell said his team will use the deliberate offense it used to build a 14-point halftime lead over powerful Virginia, in Charlottesville, before the Terrapins lost in overtime.