Internet portfolio company United Online Inc. has sold social media network StayFriends to Stroer Content Group of Cologne, Germany for $18.3 million.

The move is part of the company’s “strategy to exit the social media business following the sale of Classmates in August 2015,” said Interim Chief Executive Jeff Goldstein, in a statement.

Despite having a number of steady business units, such as NetZero and Mypoints, United Online has been slow to pursue new, higher-growth industries. The company has focused on divesting itself of businesses; selling off floral ecommerce site FTD Cos. Inc. in 2013, and Classmates.com for $30 million in August.

Declining revenue and a stagnant stock price has frustrated some of United Online’s shareholders. The company is fighting a group of activist investors, led by former Activision chairman Howard Marks, who are campaigning to replace the company’s board of directors.

United Online’s revenue shrank 9 percent to $151 million last year. The company’s shares on Friday closed down 8 cents to $ 11.46 on the Nasdaq.

Technology reporter Garrett Reim can be reached at [email protected]. Follow him on Twitter @garrettreim for the latest in L.A. tech news.