comScore and Rentrak said that the merger of the two companies was approved in separate meetings of their shareholders.
The deal is expected to close by the end of business Friday, Jan. 29, with Rentrak becoming a wholly owned subsidiary of comScore.
The combined company is expected to become a more formidable competitor to Nielsen, the leader in the audience measurement business.
comScore is specialized in web measurement and has been doing work in cross-platform metrics.
Rentrak has a growing local TV ratings business and is a leader in measuring VOD consumption. It uses set-top box data to provide census-based data. Rentrak also does box-office tallies for the movie industry.
Also after the close of trading on Friday, comScore will join the S&P MidCap 400 Index, moving from the S&P SmallCap 600 Index.