Kirkland & Ellis is advising the chairman and CEO of Qihoo 360 Technology Co. Ltd. and a consortium of private equity investors in a $9 billion bid to take the NYSE-listed Chinese Internet security company private.

The offer of $77 per American depositary share would make Qihoo's delisting the largest such transaction by a U.S.-listed Chinese company, overtaking Focus Media and its $3.7 billion going-private deal in 2012. The company's shares closed at $70.15 on Wednesday.

Kirkland partners David Zhang and Jesse Sheley in Hong Kong are acting for the take-private consortium. In 2014, Zhang represented Qihoo on a $1 billion issue of convertible senior notes—the largest-ever convertible bond issue by a U.S.-listed Chinese technology company, according to the firm. He also advised the company on its $175 million initial public offering in 2011, though he was a partner at Latham & Watkins at the time.