HBO and Sky have inked a $250 million co-production deal for high-end dramas with the hope of creating the next Game of Thrones, as well as bulking up the pair’s combined content portfolios to challenge Netflix. The two companies plan to screen the first show in 2018 and green-light at least two dramas a year. Vivendi has been given one year to cut its stake in either Mediaset (28.8%) or Telecom Italia (24%) after the Italian communications regulator Agcom ruled that its stake-building actions in the two companies is in breach of antitrust laws. Vincent Bollore’s Vivendi has been given 60 days to submit a plan of action, and argued in a statement that it “neither controls nor exercises a…