The Pittsburgh-area McDonald's franchisee who created the Big Mac nearly 50 years ago has died. Michael "Jim" Delligatti was 98 years old.

McDonald's spokeswoman Kerry Ford confirmed Wednesday that Delligatti died at home surrounded by his family Monday night.

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Delligatti's franchise was based in Uniontown, just outside Pittsburgh, when he invented the chain's signature burger in 1967 using two all-beef patties, a "special sauce," lettuce, cheese, pickles and onions on a sesame seed bun.

After several naming trials, the Big Mac was released nationwide the following year.

In the sandwich's storied history, McDonald's has rarely tinkered with the recipe until this year when it began testing a spicy, Sriracha sauce on the burger. Next year, the chain plans to roll out two different sizes-- a smaller “Mac Jr” with just one beef patty and a larger “Grand Mac” with 66 percent more beef than the original sandwich, extra cheese, more sauce and an even bigger bun.

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Delligatti told The Associated Press in 2006 that the Oak Brook, Illinois-based McDonald's resisted the idea at first because its simple lineup of hamburgers, cheeseburgers, fries and shakes was selling well at the time.

Now the chain sells over half a billion Big Macs annually and the burger is known as McDonald's signature sandwich around the world.

The Associated Press contributed to this report.