Once upon a time, there was Kraft, home to blue-boxed mac-and-cheese and several other grocery store favorites. Then there was Kraft Heinz, bringing your ketchup and other condiments together with your cookies and cheese. And now, if Kraft Heinz gets its way, they might be joined by European mega-conglomerate Unilever, tying half your grocery store together under one big corporate umbrella.

Many media outlets, including Fortune, report this morning that Kraft Heinz has made an offer to buy Unilever for $143 billion… and that Unilever rejected the bid.

Kraft, however, is not giving up. “While Unilever has declined the proposal,” it said in a statement, “we look forward to working to reach agreement on the terms of a transaction.”

Unilever, however, claims that they’re completely disinterested. “Unilever rejected the proposal as it sees no merit, either financial or strategic, for Unilever’s shareholders,” it said in a statement. “Unilever does not see the basis for any further discussions.”

Just the rumor, however seems to have been good for business: Stock prices for both companies jumped up after the news broke.

The full list of Kraft Heinz brands includes not only those two headliners, but also a huge array of other supermarket staples including Oscar Mayer meats, Maxwell House coffee, Planters nut products, and Jell-O, among many others. They are, however, all in some way food-related or edible.

Unilever’s many brands, on the other hand, span every aisle of the store. Not only do they own Hellmann’s mayo, they also own a whole slice of the freezer section with Popsicle, Ben & Jerry’s, Breyer’s, Talenti, and Klondike under their belt. Then of course there’s the personal care lineup, including Dove, Axe, St. Ives, Caress, and Vaseline, among many others. And that’s not even counting some of the many hundred brands it owns that are more notable overseas than in the U.S.

If such a deal were ever to come to fruition, it would be one of the largest mergers of all time — and would face regulatory scrutiny both by U.S. regulators and by their counterparts in Europe.

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