The U.S. Federal Communications Commission on Thursday gave final approval to AT&T Inc's $944 million bid to buy Centennial Communications Corp.

The widely expected move comes three weeks after the U.S. Justice Department approved the deal on the condition that AT&T, the No. 2 U.S. wireless provider, divest Centennial operations in parts of Louisiana and Mississippi.

The FCC granted the approval under the same conditions.

It also required AT&T to continue Centennial's roaming agreements for four years under certain subscriber conditions. The agency also said it accepted AT&T commitments to maintain a CDMA network in Puerto Rico and the U.S. Virgin Islands for 18 months. AT&T operates on the alternative GSM network.

AT&T, which was required to sell eight service areas, has reached an agreement to sell five of them to Verizon Wireless, a venture of Verizon Communications Inc and Vodafone Group Plc.

In a bit of a swap, AT&T also agreed in May to buy Alltel Wireless assets that Verizon was required to sell as part of its purchase of Alltel.

Centennial, based in Wall, New Jersey, is the 8th largest wireless provider and offers service in six states, Puerto Rico and the U.S. Virgin Islands, the Justice Department said. AT&T estimated Centennial had about 1.1 million wireless subscribers.

Shares of Dallas-based AT&T closed 41 cents higher Thursday, or 1.6 percent, at $25.94 on the New York Stock Exchange.

The deal was first announced in November 2008 and approved by Centennial stockholders in February.

To address limitations on overlapping boards, AT&T also said it would maintain an arms-length relationship with America Movil SAB de CV, which is controlled by Mexican billionaire Carlos Slim.

One of AT&T's board members is Jaime Chico Pardo, who was also a director of America Movil until June. Pardo is also chairman of Mexican telephone giant Telmex, which is controlled by Slim.

AT&T also owns a 9.75 percent stake in Telmex and has an 8.82 percent investment in America Movil, the FCC said.

In the United States, Mexico City-based America Movil provides prepaid phone plans under its TracPhone Wireless Inc unit. That service runs on the Verizon Wireless network.

(Reporting by John Poirier; Editing by Steve Orlofsky)