EAST RUTHERFORD, N.J. (AP) New Jersey Nets center Alonzo Mourning is leaving basketball again because the kidney disease he's had for three years is worsening and he needs a transplant.

The announcement Monday comes just a few months after Mourning signed a four-year contract with the Nets believed to be worth $22 million. The four-time All-Star sat out all of last season and large portions of two of the last three years because of the kidney ailment.

The team said a nationwide search is underway for a prospective kidney donor.

``It is with great sadness that I make this announcement,'' Nets president Rod Thorn said. ``Alonzo is a true champion and a very courageous athlete who attempted to defy the odds with his comeback to the NBA.

``Unfortunately, his medical condition will not allow him to continue his basketball career,'' he said.