Twenty-First Century Fox Inc (O:FOXA) has triggered a 46 day deadline to raise its bid for Sky (L:SKYB) in a battle with Comcast (L:CMCSA) for control of the British pay-TV group.  

Under British takeover rules, Rupert Murdoch’s Fox now has until Sept. 22 to trump Comcast's 14.75 pound per share offer for Sky, which values the broadcaster 25.9 billion pounds ($33 billion), after it formalized its own 14 pounds per share bid.  

Comcast gatecrashed Fox's attempt to buy the 61 percent of Sky that it does not already own earlier this year and the U.S. cable giant's latest, higher offer, which it submitted in July, has been recommended to shareholders by the broadcaster's independent directors.