MSNBC.com has acquired social networking site Newsvine in order to stake its claim in the growing "citizen journalism" movement occurring in the broader media industry.

The acquisition is MSNBC.com's first in its 11-year history. MSNBC is a joint venture between Microsoft and NBC, with the Web site acting as an extension of the online television network.

Both companies will remain separate, however each will integrate the other's technology. MSNBC.com paid all cash for the deal, but the exact amount as well as other terms have not been disclosed.

MSNBC.com says that it will incorporate many of Newsvine's community features into its site. "Coming together allows us to take advantage of the tremendous market opportunity to expand social media and community features across all of our brands," MSNBC Interactive News president Charlie Tillinghast said in a statement.

Newsvine will continue to be headquartered in Seattle and will retain its leadership structure. It is the third social news site to be acquired in the past 18 months - Newroo was purchased by Fox in March 2006, and Reddit was acquired by Conde Nast last October.