Gary Forsee, the man groomed to be the next chief executive officer of BellSouth, takes over as CEO at Sprint as of today.

Sprint’s board of directors formally offered Forsee the job at a meeting Tuesday night followina a court decision in its favor. He accepted and starts today.

US District Court Judge William Webster, acting as an arbitrator between BellSouth and Sprint in the dispute over Forsee’s hiring, ruled that Forsee could not be prevented from taking the Sprint position. BellSouth also lost a legal fight in a Georgia state court over a non-compete clause Forsee had signed. BellSouth is appealing that ruling to the state’s Supreme court.

However, Webster also ruled that Forsee will be restricted in his dealings with Sprint and disclosing proprietary information he knows about BellSouth. For example, Forsee was chairman of Cingular, a wireless company owned in part by BellSouth. Sprint PCS is a competitor. Therefore Forsee would have to sign affidavits every three months over the next year and a half certifying that he had not disclosed any financial, marketing, product, advertising or merger and acquisition ideas about Cingular to Sprint PCS. He also can’t approach certain existing BellSouth customers.

“It would be economically harmful to BellSouth and Cingular if Sprint, a direct competitor, had access to the confidential information that Mr. Forsee knows. The harm … would be incalculable,” Webster said in his ruling.

In a statement issued after the ruling, Sprint said the restrictions were expected and that the company is “pleased that Gary Forsee can now join Sprint.”

BellSouth said it would continue to pursue the dispute about Forsee’s non compete clause in state court.

“BellSouth has always believed it had a duty and responsibility to protect confidential information and trade secrets from disclosure to competitors,” the company said in a statement, “and we will pursue these matters in the best interest of our shareholders and employees.”

Forsee was recruited by Sprint to replace CEO William Esrey and its No. 2 executive, Ronald LeMay.