AT&T (T) agreed to buy Lumen Technologies' (LUMN) Mass Markets fiber internet connectivity business for $5.75 billion in cash, sending shares of the Denver-based firm soaring in premarket trading Thursday.

AT&T said acquiring the business would expand its high-speed fiber internet network and give it around 1 million additional fiber customers with a reach of more than 4 million f♒iber locatio🐷ns across 11 U.S. states.

"We're leading the race to connect more Americans with fiber, the best broadband connectivity technology available," AT&T CEO John Stankey said.

AT&T said it "now expects to reach approximately 60 million total fiber locations by the end of 2030—roughly doubling where AT&T Fiber is available today." The telecom giant, which also affirmed its full-year outlook and share repurchase plans, said it expects the deal to close in the first half of 2026.

Lumen shares, which entered Thursday down almost 30% in 2025, jumped 14% in premarket trading. AT&T shares, which began the day up 20% this year, were little changed.