Deutsche Bank is advising Bertelsmann on a possible takeover of RTL Group, the broadcaster, after the German media group increased its holding in the company to 89%.

Bertelsmann bought 22% of RTL from Pearson, the publishing conglomerate, for €1.5bn ($1.3bn). It paid €44 a share for the Pearson holding, and is considering trying to buy the remaining RTL shares for the same price.