(Reuters) -T-Mobile will buy substantially all of regional carrier United States Cellular's wireless operations, including customers, stores and 30% of its spectrum assets, in a deal valued at $4.4 billion, the telecom giant said on Tuesday.

U.S. Cellular's shares jumped more than 7% in trading before the bell.

U.S. Cellular will retain ownership of about 70% of its spectrum as well as 4,400 telecom towers. T-Mobile said it will lease space on at least 2,600 towers.

T-Mobile will fund the deal in a combination of cash and up to $2 billion of debt it will assume through an exchange offer to be made to some of U.S. Cellular's debtholders.

T-Mobile said it does not expect the deal to affect its financial forecast or shareholder return program for 2024.

It expects the deal to yield about $1 billion in operating expense and capital spending cost synergies.

The deal is expected to close in mid-2025 after regulatory approvals.

Verizon was in talks to also buy parts of the regional carrier, WSJ reported earlier this month.