If called before Major League Baseball investigators, Pete Rose plans to say an ex-friend's effort to blackmail him led to accusations that the Cincinnati Reds manager bet on professional ballgames, say sources close to the inquiry.

Four sources, none of whom would permit their names to be used, say Rose will tell investigators that Paul Janszen, a bodybuilder friend now serving a six-month sentence for evading income taxes, tried twice last fall to blackmail him for $40,000.But Rose will say he rebuffed Janszen, who first threatened him, then lied to the commissioner's office that Rose bet on baseball games, including Reds games.

"It was extortion and blackmail," one source said.

Another said that Rose will tell baseball investigators that Janzen, who's from the Cincinnati area, contrived the betting story and eventually took it to the commissioner's office, leading to the inquiry.

"Janszen is believeable. He cried when he told them," a source said. "They lapped it up."

Rose's attorneys have told baseball commissioner A. Bartlett Giamatti and special investigator John Dowd of the alleged blackmail attempt, the sources say.

However, Rose has not been asked about it, they say.

Janszen's attorney, Merlyn Shiverdecker, refused Thursday to comment and would not allow Janszen to be interviewed.

Rich Levin, a spokesman for Major League Baseball, said the commissioner's office would not comment on any aspect of the inquiry.

Since February, Rose has been under investigation by baseball for "serious allegations," reportedly involving gambling. He could face a one-year suspension if he bet on baseball games, and a lifetime ban if he bet on Reds games.

A federal grand jury also is investigating Rose for possible evasion of taxes involving gambling earnings.

Rose has remained essentially silent about both inquiries, except to say he never bet on baseball and never used bookies to place bets. He also says that he is cooperating with the commissioner's office and vows to tell his story when Giamatti is ready to listen.

Rose was not available for comment Thursday.

Here is the sequence of events that sources say Rose plans to outline to baseball investigators:

- Late last summer, Janszen contacted Rose's lawyer-agent, Reuven Katz, and asked to borrow $10,000 from Rose to pay lawyers' fees. Katz will not comment on the incident.

The sources say Katz contacted Rose, who said he would loan the money to him because he was a friend. Katz questioned Rose about Janszen, but Rose vouched for him.

Rose and Janszen became friends in 1986, when they were introduced at Gold's Gym in a Cincinnati suburb by Tommy Gioiosa, the gym's former manager.