With their former rivals RelevantKnowledge and Media Metrix now merged into a single entity (CI No 3,515), TV ratings giant Nielsen Media Research and net ratings wannabe NetRatings Inc had little choice but to join their respective web audience measurement initiatives into one competitive service. The expected announcement of Nielsen NetRatings came on Tuesday. Nielsen says it will handle the research and sampling side of the business, using NetRatings’ measurement software. NetRatings says it has already started work on the necessary changes to the system. The companies hope their first joint report will be ready early in 1999. Under the terms of the agreement, Nielsen picks up an equity stake in Milpitas, California-based NetRatings. Two Nielsen executives will join the board of directors of privately held NetRatings.