MSN officially announced that it is planning to launch a test version of a keyword bid management platform - MSN Keywords - in October, reports ClickZ. The pilot program will be limited to 500 marketers, by invitation only. The news, anticipated for some months now, comes as Ask Jeeves on Monday announced its own PPC platform and Yahoo on Wednesday introduced its contextual ad network for small publishers.

All three are gunning for Google in what is among online advertising's fastest-growing segments - projected to rise 40 percent to $5.4 billion in the U.S. this year, from $3.9 billion last year, according to eMarketer, writes the Wall Street Journal.

A version of MSN Keywords is now being tested in Singapore and France, Microsoft said. The product is one tool among others that will form Microsoft's new advertising service, called MSN adCenter, which Microsoft executives say will allow advertisers to tailor advertisements by giving them more information on web users than is now available.

Google in April unveiled an initiative giving advertisers more control over where their ads appear and how they are priced.

Until Keywords is released, MSN will continue to rely on Yahoo to provide PPC listings for MSN Search. That agreement expires in a year.