Comcast offers $31B for media firm Sky, rivals Murdoch's bid

US' largest cable operator Comcast has offered to buy UK-based media giant Sky for $31 billion. The offer is 16% above the existing offer from media tycoon Rupert Murdoch's 21st Century Fox. UK's competition regulator had provisionally halted the Fox bid to buy the remaining 61% of Sky citing possible market dominance.