NEW YORK OVERNIGHT : Belafonte Weighs Mandela-Poitier Miniseries

MANDELA TV STORY TO STAR SIDNEY POITIER?: It’s a story that would ring up Big Numbers on TV. And, we hear, that’s just what Harry Belafonte and ABC-TV also believe.

According to our Hollywood spies, network moguls are supposed to be “seriously discussing” a miniseries on the life of Nelson A. Mandela that would be produced by Belafonte. Bill Cosby’s wife, Camille, who is also a producer, likewise has been mentioned as one of the brains behind the project.

According to a top source, the film would star Oscar-winner Sidney Poitier as the South African hero, with other roles reportedly being offered to Jane Fonda and Marlon Brando. Harry Belafonte also would make an appearance in the movie as Archbishop Desmond Tutu.

While the entire project is cloaked in secrecy, with the Poitier and Cosby offices refusing to return repeated phone calls, a spokesperson for ABC-TV did confirm Wednesday that “a Mandela miniseries property is presently in the development stage.”

“But for competitive reasons that’s all we’re going to say on the subject.”

Poitier is currently doing a two-part series for ABC-TV on the life of Supreme Court Justice Thurgood Marshall for the 1990-91 season.

SYD MAKES A PITCH: This time last year, Syd Thrift was gearing up to open the baseball season as Yankee owner George Steinbrenner’s main man. Well, you know how things are with George. It didn’t last.

So now Thrift is Down South managing his company and making plans to launch his book, “The Game According to Syd.” But don’t get the idea this will be a knock on George.

“This was written to have a positive impact on baseball. It’s for the fan and to improve what he sees at the game,” Syd said. Still, Syd does have a paragraph or two on The Boss.

As for the lockout’s affect on this season, Thrift sees few problems. “We’ll have quality baseball because most of the players stay in condition all year,” he said. “If you have a young team, the entire spring training season is a necessity. But the set teams will get off the blocks all right.”

And the Yankees? “They’re a much better team than last year. They’ve improved the pitching significantly.”

HARMONY?: Show biz folk will be paying close attention to the interaction between Dorothy Loudon and Martin Charnin when Dot takes in Marty’s cabaret show at Rainbow & Stars tonight.

Friends say they haven’t been on the warmest of terms since “Annie 2” crashed in Washington. Warm? Try frigid.

“They had a misunderstanding,” is the way an acquaintance of the two put it Wednesday. “Maybe this signals a thaw.”

Loudon, of course, won a Tony for portraying Miss Hannigan in Charnin’s original production. But even though the show’s being reworked at Goodspeed in Connecticut, Dot’s not a part of it.