Nelson Peltz, the head of Trian Fund Management, said France’s Danone is undervalued and his firm plans to “engage” with management to urge the company to avoid dilutive mergers and acquisitions.

Danone, the world’s largest yogurt maker, is worth 78 euros (about $99.50) a share, Peltz said at the Invest for Kids conference in Chicago.

The stock climbed the most in a year yesterday after the Financial Times reported the billionaire investor had taken a 1 percent stake.