Even as Alibaba Group Holding Ltd prepares for what could be the largest tech initial public offering in history, its top officials are racking their brains on ways to retain talent.

The initial public offering, which analysts estimate could value the Chinese e-commerce behemoth up to $170 billion, could generate more than a handful of millionaire employees after their shares are unlocked. Company officials are apprehensive that the these new millionaires may want to move on, thereby leaving the company bereft of several key personnel.

According to Alibaba's draft prospectus, current and former employees hold 26.7 percent of the existing shares, and many of then have enhanced their holdings through stock options and other incentives since 1999.