Jupiter shareholders will receive 0.946 shares of Media Metrix for each share held. The merged company will be called Jupiter Media Metrix and will have a combined market value of $1 billion, the companies said.
Media Metrix measures Internet traffic and audience size online. Its measurement data has become a de facto standard in determining the leading sites on the Web. Many sites commonly refer to Media Metrix numbers as a way to market the popularity of their services.
The deal with Jupiter will add in-depth Net market data to Media Metrix's offerings, the companies said. Jupiter sells its market research to corporate clients and organizes industry conferences.
Earlier this year, Jupiter paid $50.6 million in cash and stock to acquire privately held Internet Research Group and Net Market Makers in an attempt to offer more business-to-business research.
Media Metrix's primary competitor is Nielsen/NetRatings. Similar to its measurements of TV viewers, Nielsen/NetRatings offers metrics on Web traffic.
For Media Metrix, the merger with Jupiter will allow the company to offer market research derived from its audience data--something the company could not previously do because of perceived conflict of interest, according to analysts.
"Clearly the opportunity here is that Jupiter could take this raw data and mine it and write research reports," said Jeff Baker, an analyst at SunTrust Equitable. "Media Metrix couldn't do that in-house without risking the perception that it's compromising some of that data."
Tod Johnson, Media Metrix's chairman and chief executive, will retain his title in the newly merged company. Gene DeRose, chairman and CEO of Jupiter, will become president and vice chairman of Jupiter Media Metrix. Mary Ann Packo and Kurt Abrahamson, chief operating officers of Media Metrix and Jupiter, respectively, will serve as co-COOs of the new company.
The new company will trade under the symbol "MMXI" on the Nasdaq Stock Market.
Reuters contributed to this report.