German competition regulators may block the sale of ProSiebenSat.1, a publishing and broadcasting group owned by a consortium of private equity firms, to Axel Springer, publisher of the mass-circulation tabloid Bild.

The Wall Street Journal reports that two regulatory bodies, the German cartel office and the Commission to Investigate Media Concentration, are investigating the deal after several competitors and politicians complained about concentrating media assets in Axel Springer's hands.