* Yum China's board decided not to pursue the offer - sources. : HONG KONG (Reuters) - Fast-food chain operator Yum China Holdings Inc (YUMC.N) has rejected a $17.6 billion 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 Tuesday’s closing price, for the biggest fast-food chain in China, the people said.