(Sharecast News) - Comcast said it had bought more than 30% of Sky's shares to make its £30.6bn cash bid for the UK broadcaster mandatory.The US cable company said it had bought 515,885,170 Sky shares at its offer price of £17.28 a share - 125% more than the shares' value before Fox kicked off a long bidding war in December 2016. Under UK takeover rules if a company acquires more than 30% of another company's shares it has to offer to buy the whole company.Comcast said it would buy more Sky shares in the market. It won an auction for the FTSE 100 company on Saturday against Rupert Murdoch's 21st Century Fox that will draw a line under Murdoch's association with the company he founded in 1989. Fox bid £15.67 a share in the auction held by the Takeover Panel.Sky has urged its shareholders to accept Comcast's offer promptly. Shareholders have until 13:00 UK time on 11 October to accept the offer. Fox holds 39% of Sky, a stake it is selling to its bidding partner Disney.Comcast said: "Comcast Bidco will continue to acquire Sky shares in the market from eligible shareholders outside the United States at up to and including £17.28 in cash for each Sky share ... All Sky shareholders are urged to proceed to accept the second increased offer."Analysts said Comcast's offer was a big payday for Sky shareholders. The US company has said Sky will operate independently after the takeover. Comcast is expected to use Sky as a launchpad for new digital services as it tried to combat streaming providers such as Netflix and Amazon.The deal brings to an end one of the longest and most convoluted UK takeover battles. Having tried to buy all of Sky before, Murdoch instead decided to sell his entertainment operations, including Fox's Sky stake, to Disney in November 2018. But Comcast thwarted the plan, making a rival bid for the Fox assets that forced Disney to increase its offer and then a separate successful offer for Sky.