European broadcast and entertainment giant RTL Group has bought a 65% stake in online video ad platform SpotXchange for $144 million, plus an earnout based on performance and an option to buy the remaining 35%. SpotXchange will continue to operate as an independent company, with CEO Mike Shehan saying that funds will be used to accelerate growth, particularly in Europe.

SpotXchange primarily serves publishers to help them monetize their online video ad inventory. The company's programmatic marketplace runs over 400 million auctions per day with video ads reaching over 200 million unique visitors per day globally. SpotXchange was in sixth place in comScore's June '14 ranking of ad properties with a 32.8% reach to the U.S. population. In Q1 '14 it reported a 145% revenue increase vs. Q1 '13. SpotXchange previously said that in 2013, programmatic accounted for 46% of its revenue.

The deal continues the wave of financings and M&A in the video ad tech space over the past year plus, including AOL-Adap.tv, Comcast-FreeWheel, Facebook-LiveRail, Opera-AdColony, Extreme Reach-BrandAds and TubeMogul's recent IPO, among others.

RTL operates 53 TV channels and 27 radio stations throughout Europe and also owns FremantleMedia, which produces 8,500 hours of programming per year and distributes over 20,000 hours of content globally. Fremantle also runs over 150 channels on YouTube and last year bought a 51% stake in BroadbandTV, a big Canadian multichannel network (MCN).