China's Qihoo 360 Technology Co. Ltd., a provider of Internet security products and popular mobile browser, has received a $9.1 billion offer from a group led by its chief executive to buy out its public shareholders. The $9.1 billion offer for Qihoo's U.S.-traded shares is the biggest yet in a wave of proposals this year to take Chinese companies private at a time of surging stock prices at home and increased scrutiny of their finances by foreign shareholders. Chinese technology companies turned to U.S. and other foreign stock exchanges over the past decade to raise money due to lack of access to the state-dominated financial system at home. Communist leaders have promised to give private companies more access to China's stock markets and other financing in an effort to make its economy more productive.