T-Mobile USA is working on finalizing a new business plan to try and stem consumer losses, rebuild its brand and win over wholesale customers after its failed sale to AT&T Inc, the chief executive of the Deutsche Telekom unit said.

T-Mobile USA is alive and we are back in fighting spirit, CEO Philip Humm told reporters at the Consumer Electronics Show in Las Vegas, promising more details later in the quarter.

After what he called nine months in limbo - when the company and AT&T fought unsuccessfully to secure U.S. approval and seal a $39 billion AT&T acquisition - Humm said the company's brand needed reinvigorating, and its network needed more investment.

(Reporting By Sinead Carew; Editing by Richard Chang)