Renren (RENN) hopes to boost the value of its American Depositary Shares by repurchasing big chunks of them. The company's board has authorized a buyback program for up to $100 million worth of ADSes. The program is effective as of today, and will be in force for one year.

This replaces an existing $150 million initiative that had nearly been exhausted. That effort was launched in September 2011.

The buybacks for the current program will be effected through various means, including open market purchases, block trades, privately negotiated buys, and other "legally permissible ways".

In the press release announcing the move, Renren quoted its CEO Joseph Chen as saying that, in spite of the expense, the firm will "continue to focus on our long-term strategy of building a sustainable business around mobile-centric social networking." 

Currently, Renren has more than 377 million shares outstanding. Its most recent closing stock price was $2.99 per share.