What? The snack food market is looking like a hotbed of activity as speculation mounts that PepsiCo (NASDAQ:PEP) will acquire Mondelez International (NASDAQ:MDLZ).

So what? Pepsi's Frito-Lay division is the biggest snack foods company, with $13.6 billion in 2012 revenues, accounting for more than a fifth of the beverage maker's total. Mondelez is itself an international snack foods giant, born of the divestiture of its old U.S. grocery business into Kraft Foods (UNKNOWN:KRFT.DL), and sporting $35 billion in global sales, of which North America represents 19% of the total, or around $6.7 billion .

The Wall Street Journal speculates that with activist investor Norman Peltz taking a sizable position in both companies, a merger of their snack foods business may be in the works. At the least, Pepsi might spin off its snack foods business, though there's a third possibility: that a spinoff and merger could both happen.

Kellogg (NYSE:K) was catapulted into the No. 2 position in the snack foods industry following its acquisition last year of Proctor & Gamble's Pringles chips business. It enjoyed an 18% surge in net revenues primarily as a result of Pringles, noting that without the acquisition, sales growth would have come in just 5.3% higher. That might have made it the biggest gain it's seen in more than a year, but it's obvious the snacks business is what is powering growth.

Now what? Peltz might be joined in the spinoff-merger effort by Relational Investors, another big shareholder with a $519 million investment in Pepsi that's also been agitating for change.

Norman Peltz was one of the driving forces behind Cadbury splitting its drinks and candy business in two, then pushing Kraft to acquire it, which annoyed Warren Buffett so much he sold down his stake in the company. Peltz then pushed for the Kraft split-up into Mondelez and Kraft.

It might not happen right away, but Peltz has a way of shaking things up when he sets his mind to it, and a merger of PepsiCo and Mondelez would create a $170 billion behemoth.