AT&T said Sunday it plans to acquire Bellevue-based T-Mobile for $39 billion. Both companies have immense local presence.

T-Mobile’s headquarters are in Bellevue’s Factoria area, while AT&T has a regional hub in Bothell. The fate of those offices remains unclear at this point.

Colleen Smith, a spokeswoman for AT&T in Washington, said it’s too early yet to determine changes in staffing levels at various efforts, but she said the company remains committed to having a strong base in the Puget Sound area.

“Our headquarters will remain in Dallas but we will maintain a large presence in the Seattle area,” It’s too soon to speculate on future staffing needs, but we can confirm that we’ll continue to have a large presence in the Seattle area.”

Representatives from T-Mobile did not return phone calls requesting comment, but did release a short statement highlighting the importance of T-Mobile personnel in the merger.

“There are more than 3,300 T-Mobile employees in the Seattle area, including retail store representatives, engineers and operational functions in our corporate headquarters in Bellevue, Washington,” according to a statement. “Making this combination a success will require the talent and commitment of T-Mobile USA employees.”

It should take approximately one year for the deal between AT&T and T-Mobile’s parent company Deutsche Telekom to clear federal regulatory hurdles, and in that time, T-Mobile users should notice no change.

National media outlets have reported that AT&T could face some difficulty in gaining approval from the Federal Communications Commission and Justice Department because of limited competition for wireless service that will remain should the deal clear.

AT&T has shown confidence that this transaction will be accepted by federal regulators because of the increases in service it expects for customers.

“We feel like we can get this done,” said Wayne Watts, counsel for AT&T. “The action shows significant and unique public benefits from this transaction.”

The long-term benefit for users of T-Mobile’s and AT&T’s mobile platforms comes in the form of increased broadband Internet service through mobile phones. The deal will allow AT&T to offer’s its newly expanding 4G Long Term Evolution (LTE) network to 95 percent of the U.S. population, including many rural areas in small towns.

AT&T representatives have said the company’s commitment to expanding some form of broadband access to all Americans, consistent with one of President Barack Obama’s primary long-term goals, should help in the regulatory process as well.

“This transaction represents a major commitment to strengthen and expand critical infrastructure for our nation’s future,” said Randall Stephenson, AT&T Chairman and CEO. “It will improve network quality, and it will bring advanced LTE capabilities to more than 294 million people. Mobile broadband networks drive economic opportunity everywhere, and they enable the expanding high-tech ecosystem that includes device makers, cloud and content providers, app developers, customers, and more.”

Statements from both AT&T and T-Mobile state that current plans will be grandfathered in, but it remains unclear what will happen to T-Mobile users once the deal is complete and their plans expire. T-Mobile features generally less expensive plans than AT&T and is the only major carrier to offer unlimited data plans.

The sale intensifies the competition between AT&T and Verizon to claim the top spot among wireless carriers. AT&T will absorb T-Mobile’s 33.7 million customers, giving a total of 130 million customers, vaulting it ahead of Verizon.

Sitting in distant third place is Sprint, with half of AT&T’s new base. Sprint had been rumored to buy T-Mobile as well as Kirkland-based Clearwire earlier this year to add the ability to compete with the top mobile carriers.