Sept 4 (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.