HONG KONG (Reuters) - Fast-food chain operator Yum China Holdings Inc has rejected a $17.6 billion(13.67 billion pounds) buyout offer from a consortium led by Chinese investment firm Hillhouse Capital Group, quashing what would have been one of Asia's biggest deals this year, people with direct knowledge of the matter said.The Hillhouse-led consortium, which included regional investment house Baring Private Equity Asia, expressed an interest to offer $46 per share, or nearly 24 percent above..