Lori Grunin/CNET

T-Mobile USA and MetroPCS have made it official and joined forces as one company.

Known as T-Mobile US as of Wednesday, the new combined company will bring together the networks, subscribers, and other assets. The newly united carriers together hold around 43 million subscribers as of March 31.

T-Mobile US's total coverage reaches around 301 million people. A full 228 million have access to 4G, while 200 million are expected to be covered by 4G LTE by the end of the year.

Had they united last year, the combined company's revenues would have reached $24.8 billion. Management is estimating revenues to grow 3 percent to 5 percent compounded annually through 2017.

John Legere will serve at the helm as president and CEO at the company's headquarters in Bellevue, Wash. J. Braxton Carter, former MetroPCS vice chairman and chief financial officer, will serve as chief financial officer. The new company will run T-Mobile and MetroPCS as two separate brands initially, but the goal will be to move to a common network and support business infrastructure.

"The combination of T-Mobile and MetroPCS creates an even stronger disruptive force in the U.S. wireless market," Legere said in a statement. "Together, as America's 'un-carrier,' we'll continue our legacy of marketplace innovation by tearing up the old playbook and rewriting the rules of wireless to benefit consumers."

T-Mobile US begins trading today on the New York Stock Exchange under the ticker TMUS.

T-Mobile USA and MetroPCS had a rough ride to the altar.

Arguing that the deal undervalued the worth of the company, major MetroPCS investors Paulson & Co. and P. Schoenfeld Asset Management urged shareholders to vote against it. MetroPCS fought back by telling its investors it couldn't guarantee them a better value as a standalone company.

T-Mobile USA parent Deutsche Telekom eventually sweetened its offer by cutting the amount of debt owned by the combined company and reducing the interest rate. T-Mobile shareholders finally approved the deal on March 24.

MetroPCS investors will be paid $4.06 per share in cash, plus stock equivalent to 26 percent of the combined company. Deutsche Telekom will own the remaining 74 percent.