BEIJING, Sept. 18 (Xinhuanet) -- Yahoo said Monday it was buying Zimbra, a Web-based e-mail provider, for 350 million U.S. dollars in cash and stock to help it compete with Internet giant Google and social network sites such as MySpace and Facebook.

  "This to me is a further investment in parts of the Yahoo business that we are most committed to," said Brad Garlinghouse, senior vice president for communications and communities at Yahoo.

The exact terms of the deal were not disclosed, but a Yahoo spokeswoman said the purchase would be mainly made with cash, with Yahoo stock making up the difference.

Zimbra will continue to sell its product separately after the completion of the purchase to a greater number of potential customers around the world, said Satish Dharmaraj, Zimbra’s co-founder and chief executive.

Yahoo has announced early September to buy online advertising network BlueLithium for 300 million dollars in cash, a move that Yahoo attempts to regain some of the ground that it has lost during the past three years to Google.

Yahoo has also begun testing a new service dubbed "Mash," in the latest attempt to catch up MySpace and Facebook in the social networking stakes, media reported Sunday.

Social networking has been one of the hottest areas of the Web in recent years. Yahoo is trying to become a provider of third-party services not only to advertisers, but also to other Web-based businesses.

The deal comes just days after Google paid 625 million dollars to buy the online security firm Postini to target large businesses of online security services.

(Agencies)