Private equity firms Permira and KKR are said to be working with JPMorgan Chase on options for their 53% stake in German broadcaster ProSiebenSat.1 Media. The firms could sell to another company or on the open market, Bloomberg reports, and potential bidders could include Time Warner, Comcast and News Corp., The Financial Times said. News of a potential sale comes amid increased movement in the German broadcast sector as companies compete in a contracted ad sales market. In December, Discovery Communications said it was acquiring ProSieben’s SBS Nordics operations for $1.7B and last week, media giant Bertelsmann said it was considering reducing its stake in FremantleMedia owner the RTL Group. KKR and Permira acquired their ProSieben stake for 3.1B euros ($4.2B) in 2006, at the peak of the buyout market, but have had to write down their investments since. ProSieben’s stock has jumped by more than 20% since the beginning of 2013, giving the company a market value of 5.6B euros ($7.6B), according to the FT.