Reliance Broadcast Network, part of the Anil Dhirubhai Ambani group, said on Sunday it had signed an initial agreement for an equal joint venture with US-based CBS Corp to launch television channels in India.                                            The joint venture will operate English language channels and will later explore launching regional-language general entertainment channels, it said in a press release.                                           
"The agreement is subject to customary diligence, negotiation and execution of a definitive documentation, which are presently underway," it said, adding it plans to complete the process in a month.                                             
No other details were provided.