Billionaire investor Nelson Peltz has built stakes in food makers PepsiCo Inc. and Mondelez International Inc., the Daily Telegraph reported today, citing people it didn’t identify.

The size of the stakes taken by Peltz’s Trian Fund Management LP is unclear, the newspaper said, citing one person as saying that Peltz has spent at least $2 billion on his latest foray into the food industry. Peltz could push for a merger of the two companies, the Telegraph said, citing unidentified people in London.

PepsiCo and Mondelez shares were little changed in early German trading today. Pepsi traded at the equivalent of $76.13 as of 10 a.m. in Frankfurt, compared with yesterday’s closing price of $76.15 in New York. Mondelez traded at the equivalent of $28.68, compared with the New York closing price of $28.56.

Jo Bradley, a U.K.-based spokeswoman for Mondelez, said the Deerfield, Illinois-based company doesn’t comment on “market rumors or speculation.” Spokespeople for Purchase, New York- based PepsiCo and New York-based Trian couldn’t be reached outside of normal business hours.

Peltz, 70, is an activist investor who takes stakes in companies, particularly those in the food and restaurant sectors, and then frequently pushes for changes designed to boost their share prices.

The billionaire’s $300 million purchase of iced-tea maker Snapple in 1997 paid off when he sold it for $1.45 billion three years later. He also bought a stake in British confectioner Cadbury Schweppes Plc and pushed for a spinoff of its soda unit, prior to its 2010 takeover by Kraft Foods Inc. He also invested in ketchup maker H.J. Heinz Co., which Warren Buffett’s Berkshire Hathaway and 3G Capital agreed to acquire this year.

PepsiCo Stake

In November 2011, Trian reported purchasing a $146 million stake in PepsiCo, the maker of Frito-Lay chips. Earlier that year, Peltz bought a $420 million stake in Kraft, which spun out its snacks business under the name Mondelez last year. Mondelez’s brands include Oreo cookies and Trident gum.

Shares of PepsiCo and Mondelez have both outperformed the Standard & Poor’s 500 Index over the past 12 months, with PepsiCo up 16 percent and Mondelez rising 14 percent, compared with the U.S. benchmark’s 11 percent gain.