T-Mobile has revamped the look of its spokeswoman and model, Carly Foulkes, by ditching her pink dress for black leather. The ad is part of T-Mobile's wider marketing effort to be competitive with Verizon and AT&T.

The brief ad is on YouTube, where Foulkes exchanges her magenta frock for black leather and approaches a Ducati bike. It shows Foulkes driving away on the bike with the tagline "No More Mr. Nice Girl."

The ad is part of a rebranding process as T-Mobile lags behind Verizon and AT&T. T-Mobile is not stocking the iPhone like its competitors, so other ways to gain attention are needed.

During the second half of the year the company will continue to re-brand.

"We're working toward a brand refresh later in the year. We really can't wait until the end of the year to make some noise in the market," T-Mobile Senior Vice President Peter DeLuca said in an interview with AllThingsD.

DeLuca also said the new ad campaign will debut on TV. The carrier will also be investing $200 million in advertising spending. The company will be using pre-roll ads on Hulu and "takeover ads" on YouTube, where specific videos are launched and video pages are altered to reflect the product.

There will also be a Web site which compares T-Mobile's devices to the iPhone, in a move that sounds similar to Microsoft's "Smoked by Windows Phone" challenge where users are asked to perform a task in a quicker time than a Windows Phone 7 device.

The carrier is backing up the rebranding efforts with new products, launching the HTC One S later this week in New York. There will be ads to go alongside the device.

"We really want to set the record straight and say to the consumer they really should be taking a second look at T-Mobile," DeLuca added.

T-Mobile's parent company Deutsche Telekom has committed to investing $4 billion, as LTE is brought to the network. That isn't arriving until next year, though, so T-Mobile will continue to push HSPA+ - an improved version of 3G.

Check out the cool T-Mobile video below. Carly is sizzling in the new outfit.

(reported by Jonathan Charles, edited by Surojit Chatterjee)