Rollie Massimino stunned the New Jersey Nets and relieved Villanova University yesterday when he rejected an offer of a pro contract that reportedly would have made him one of the five highest-paid coaches in the National Basketball Association.

He decided early yesterday morning after all-night talks with the Nets. Club President Bernie Mann had announced Tuesday that Massimino was ready to sign a contract reportedly worth $2.1 million over 10 years.

But Massimino made his own announcement about 7 a.m. yesterday, just hours before the Nets were to hold a press conference to announce who would replace Stan Albeck, who left to coach the Chicago Bulls. The Nets canceled the press conference and a team spokesman said the club will begin reassessing options today.

"I felt it was in the best interests of my family, Villanova, our players and Jake Nevin," Massimino said in a statement released by the university. "The decision was very trying and very tiring."

Nevin, Villanova's long-time trainer, has Lou Gehrig's disease.

A Villanova spokesman said Massimino went home and slept all day after making his statement and was not available for comment.

Massimino's lawyer, Jerold K. Levien, said that Massimino had reached "a handshake agreement" with the Nets last weekend. "What turned the tide," he told The New York Times, "were segments of the transaction that we felt the Nets were changing. They were changing the deal on things like fringe benefits and a life insurance program and certain other items. Mr. Massimino felt he was being put in a position of renegotiation. That, coupled with his deep feelings for Villanova, made the difference."

"We're back to square one again," Mann told the Associated Press. "He was our No. 1 choice. It certainly is disappointing."

At Villanova, there was rejoicing over his return for a 13th season. He has a 228-137 record there and won the NCAA championship last season. He is to sign a contract next week, but Athletic Director Ted Aceto would not disclose terms.

Most of Massimino's players at Villanova believed he would leave. "From everything we read and heard, he was gone," guard Harold Jensen said. "We're just overjoyed. It was a tremendous contract . . . It tells you a lot about him."

Many Villanova players planned to celebrate last night. The team, after an emotional meeting at Massimino's home Monday night, met in his office yesterday to await his decision. He was greeted with hugs.

"I'm surprised, but Coach Mass always tells us people come before business," sophomore forward Mark Plansky said. "He would have been secure for the rest of his life, but he would have broken ties he believed in. The price was too high. It was a decision from his heart, not his wallet."