MetroPCS Communications amended the terms for its proposed merger with Deutsche Telekom unit T-Mobile USA, and asked shareholders to vote for the deal.
The move follows Deutsche Telekom sweetening its offer last Wednesday, bowing to pressure from activists and proxy advisory firms.
MetroPCS's shares, which closed at $11.52 on the New York Stock Exchange on Friday, were down 2 percent in premarket trading.
The amendment "significantly improves" the value of the proposed combination for shareholders, MetroPCS's board said in a statement.
The new terms include reducing the combined company debt by $3.8 billion to $11.2 billion and lowering the interest rate on the debt by 50 basis points.
As a part of its sweetened offer, Deutsche Telekom has expanded the lock-up period - when it is prohibited from publicly selling shares in the company - by 12 months to 18 months.
(Reporting by Sruthi Ramakrishnan in Bangalore; Editing by Sreejiraj Eluvangal)