(Reuters) -T-Mobile said on Thursday it expects to generate about $400 million more in service revenue this quarter as the U.S. wireless carrier integrates customers of the recently acquired regional rival UScellular.

U.S. antitrust enforcers greenlit the $4.4 billion deal in July after closing its investigation without seeking to block the transaction announced in May last year.

The company closed the deal on August 1, taking over UScellular's wireless operations, including customers, stores and 30% of its spectrum assets.

T-Mobile now expects synergies from the integration to help save about $1.2 billion in costs annually, up from the initial outlook of about $1 billion run rate.

It also expects to achieve the integration in about two years, compared with its initial three-to-four-year projection.

T-Mobile said it will take a non-cash charge of about $350 million in the third quarter due to its switch to a more streamlined billing platform.

The company also anticipates about $100 million in integration costs, excluded from core adjusted EBITDA, and roughly $175 million in depreciation and amortization expenses.