NEW YORK — A review of the NBA's officiating program released Thursday made recommendations for significant changes, but found no evidence of illegal activity by any referees other than Tim Donaghy.

The report, conducted over 14 months by former federal prosecutor Lawrence Pedowitz, called for the creation of a "culture of compliance" and the closer monitoring of games for suspicious activity.

While the report found that referees broke league rules involving casino gambling, none of their activities reached the criminal level. It disputed Donaghy's allegations of specific misconduct and favoritism of certain players and teams, but warned that "because the potential for referee bias remains a threat to the integrity of the game, the League can do more."

Commissioner David Stern chose Pedowitz's firm to conduct the investigation last year after former referee Donaghy was charged with betting on games he officiated and providing inside information to gambling associates to win their bets. He is currently serving a 15-month sentence.

Pedowitz's firm conducted more than 200 interviews with referees, and team and league personnel to complete the 133-page report.

"We welcome the recommendations from Mr. Pedowitz in areas where we can improve — all of which will be adopted, and many of which have already been adopted, including the hiring of Army Major General (Ret.) Ronald L. Johnson as the senior vice president, referee operations," Stern said in a statement.

"These measures are a beginning, not an end. We know that the NBA's success hinges on the integrity of our sport and on competition that allows teams to win based on their own skill and performance. We expect nothing less from our referees than the highest level of accuracy, professionalism and integrity."

The report has already sparked a number of changes. Johnson, who served 32 years in the Army, was hired over the summer. Longtime ref Bernie Fryer became the NBA's vice president and director of officials, and Joe Borgia was appointed vice president of referee operations.

Stern has asked Pedowitz to review the new program at the end of the season.