AT&T bought Wall, N.J.-based Centennial for $944 million in cash. The deal was announced a year ago, and was initially expected to close in the second quarter this year.

With the acquisition, AT&T is gaining 879,000 wireless subscribers and an expansion of its wireless network in Puerto Rico and in rural areas of the Midwestern and Southeastern U.S.

As part of a deal with regulators, AT&T has committed to selling eight Centennial service areas in Louisiana and Mississippi. In May, it reached a deal to sell five of them to Verizon Wireless for $240 million.

Centennial subscribers who are not in one of the eight markets to be divested are now AT&T subscribers. They can keep their rate plans or move to AT&T plans, the company said.