Tagged, the third-largest social networking site behind Facebook and Twitter, has acquired social networking site hi5, according to a report by the Wall Street Journal.

Hi5 was the third-largest social networking site in 2008 behind Facebook and MySpace. Tagged passed MySpace as the new third-largest for the first time in September, according to data from Experian Hitwise.

Here's what the CEO has to say, according to the Wall Street Journal:

Hi5 took a hit when Facebook went international in 2008 and started scooping up market share, said Greg Tseng, Tagged’s CEO. The company tried to reinvent itself over the last two years as a social game company, but ultimately decided a sale was its best option, he said.

Tseng, who pivoted Tagged away from social networking to the social discovery category in 2007, said the hi5 deal will double his company’s user base from 10 million active users to 20 million active users. It will also add about 200 million registered users to its already 100 million registered users.

The terms of the deal weren't disclosed.