T-Mobile this week issued a letter to SunCom customers, updating them on its upcoming acquisition of the southeastern wireless carrier and outlining its plan to support the customers going forward.

T-Mobile first announced its plans in September to purchase SunCom Wireless Holdings for $2.4 billion, in hopes of increasing its network coverage in the southeastern United States and the Caribbean. Specifically, T-Mobile will gain SunCom customers in North Carolina, South Carolina, Tennessee, Georgia, Puerto Rico, and the U.S. Virgin Islands.

SunCom has about 1.1 million subscribers and T-Mobile has about 27 million subscribers. With the acquisition, the population of potential customers in T-Mobile's service area is expected to increase from 244 million to 259 million.

In its letter issued to SunCom customers, T-Mobile's president and CEO Robert Dotson said T-Mobile is still in the process or getting all the necessary approvals to complete the acquisition. It already has been approved by investment funds Highland Capital Management and Pardus Capital Management, which together own more than 50% of SunCom's issued common stock.

T-Mobile will honor service plans of existing SunCom customers, including the SunCom UnPlan. Customers also won't have to change their phone numbers or purchase new phones since T-Mobile uses GSM/GPRS/EDGE technology like SunCom, so the phones will be compatible with T-Mobile's existing network.

CEO Dotson said in the letter that there will be other benefits for SunCom customers transitioning to T-Mobile:

For one, we will be bringing SunCom customers complete access to a coast-to-coast national wireless network. On top of this, we've committed right out of the gate to making further improvements to the SunCom wireless network in the Carolinas.