Mobile content services firm Motricity is taking over the mobile assets of its primary competitor, InfoSpace, in an acquisition worth $135 million. With the move, Motricity now manages the mobile content activities of 11 of the top 13 wireless operators in the U.S., including AT&T Mobility, Verizon Wireless, Sprint and T-Mobile.

Both companies provided mobile content storefront services for wireless operators which handled much of the on-deck ringtone, wallpaper and other sales taking place on handsets today. Much of those sales were limited to polyphonic ringtones, which with the advent of master ringtones, now make up less than 20% of ringtones sales today.

InfoSpace also worked with several record labels, including Universal Music Group, to create master ringtones. Motricity manages many content-related sales activities as search, portal design and navigation, community features and messaging services.

Infospace's executive VP of mobile, Steve Elfman, will become president and chief operation officer of Motricity as part of the deal, while Motrcity's Ryan Wuerch will remain chairman and CEO.