NEW YORK ( TheStreet) -- PepsiCo ( PEP) and Mondelez International ( MDLZ) shares were surging Friday on speculation U.S. activist investor Nelson Peltz may pursue a merger of the two companies after amassing critical stakes in both companies. Peltz, through his investment vehicle, Trian Fund Management, has built positions worth about $2 billion in PepsiCo, the food and beverage giant, and Mondelez, the Deerfield, Ill.-based snack company, the U.K.'s Daily Telegraph newspaper reported Friday, citing unidentified sources. Mondelez, which sells brands such as Cadbury, Nabisco and Oreo, was popping 4.6% to $29.88 and PepsiCo was gaining 3.5% to $78.81. Peltz may pressure PepsiCo to split its snack and beverage units or even push to force the two companies to merge, according to the Telegraph.Some investors may be in favor of these proposals as shareholders have previously urged a split of PepsiCo's more profitable snacks unit, which sells Lay's potato chips and Doritos tortilla chips, from its lagging beverage division. PepsiCo and Mondelez said that they don't comment on rumors. Written by Andrea Tse in New York >To contact the writer of this article, click here: Andrea Tse.