NuCom, whose holdings include online dating website eharmony, has made a preliminary expression of interest to buy Meet Group, the sources said, but they also said there was no certainty there would be negotiations that lead to a deal.

The sources requested anonymity because the matter is confidential. Meet Group and ProSieben declined to comment.

Meet Group shares rose as much 21% on the news and closed on Monday 5.3% higher at $5.33, giving the company a market value of $382 million (298 million pounds).

ProSieben shares were down 2.2% at 0829 GMT on Tuesday, making them the biggest percentage faller on Germany's midcap benchmark MDAX, which was barely changed.

Based in New Hope, Pennsylvania, Meet Group is a maker of internet-based apps that enable live streaming broadcasts and text-based conversations, including MeetMe, LOVOO, Skout, Tagged and Growlr.

Meet Group has struggled to challenge the dominant U.S. dating app developer, Match Group Inc. It is focusing on expanding its live-streaming platforms, modelled after the video products offered by Asian dating app providers.

ProSieben has looked to NuCom to diversify its legacy free-to-air TV business and expand its internet and social media portfolio. NuCom spans dating site Parship, energy price comparison portal Verivox and Jochen Schweizer, which sells vouchers for "experiences" like tandem parachute jumps.

"We believe the interest in Meet Group likely involves implementing Meet Group's live streaming platforms across NuCom's various dating sites, as well as potential user overlaps in Europe and Germany," Roth Capital Partners LLC wrote in a research note.

Last year, investment firm General Atlantic acquired a 25.1% stake in NuCom from ProSieben at a 1.8 billion euro ($2 billion) valuation. It increased its stake slightly in 2019.

(Reporting by Greg Roumeliotis in New York; Editing by Chris Reese/Matthew Lewis/Jane Merriman)

By Greg Roumeliotis