Legg Mason Inc.'s largest shareholder has agreed to invest at least $500 million in investment products with the company's affiliates.

Shanda Group, a global private investment group that owns about 10% of Legg Mason's outstanding common stock, will purchase additional shares of the company to increase its investment to up to 15% of outstanding common stock. The shareholder will not acquire more than 15% of the company's outstanding common stock or initiate certain actions including proxy solicitations during a three-year period pursuant to the agreement.

Legg Mason agreed to appoint Shanda Group Chairman and CEO Tianqiao Chen and President Robert Chiu to its board by June 1, 2017. Chen will join the company's board as vice chairman and will assist the company in technology innovation, and business development and brand building in Asia and China in particular.