Social-networking site Renren Inc (RENN.NYSE) plans to acquire the operator of video website 56.com for US$80 million in cash, MarketWatch reported. Renren’s shares rose slightly to US$5.37 after US market close on Monday, but its value remains down 62% from the top end of its IPO range in May. Renren has improved its bottom line in its two earnings announcements since it went public, reporting a slim profit and US$1.15 billion in cash and cash equivalents in the second quarter. However, operating expenses have also ticked up since its listing, as the company continues investing heavily in research and development, including mobile technology. The social-networking site agreed in August to merge its platform with Shanghai MSN Network Communications Technology, which operates Microsoft Corp’s (MSFT.NASDAQ) online business and chat program in China.