UPDATE 2-T-Mobile to launch new television service in 2018, acquire Layer3 TV

(Adds background on deal, share action)

NEW YORK, Dec 13 (Reuters) - T-Mobile US Inc will launch a new television service in 2018 and acquire television technology company Layer3 TV Inc for an undisclosed amount, the U.S. No. 3 wireless carrier said on Wednesday.

The moves come a month after T-Mobile and rival Sprint Corp ended merger talks. Chief Financial Officer Braxton Carter said at the time the company would instead focus on smaller, "tuck-in" acquisitions. Last week T-Mobile's board approved its first-ever share buyback program.

Layer3 TV integrates television, online video content and social media and is available online and on mobile devices in five cities across the United States, T-Mobile said.

The Denver-based startup, founded in 2013, offers more than 275 high-definition channels and 25,000 on-demand titles.

T-Mobile shares were up 1.3 percent at $64.30. (Reporting by Anjali Athavaley; Editing by Meredith Mazzilli and Susan Thomas)