Error works to Sony's advantage

Blockbuster franchises often come with crushing backend deals.

Not “Spider-Man.” Thanks to a clerical error in 1985 by lawyers for Cannon films, Sony Pictures is walking off with the lion’s share of the loot.

The saga, as chronicled in Dan Raviv’s history of Marvel Enterprises, “Comics Wars,” just published by Broadway, began in 1985, when Menahem Golan and Yoram Globus’ Cannon Films bought film rights from Marvel for $225,000.

Carolco later bought “Spidey” rights from Golan for $5 million, bringing James Cameron aboard to helm the pic. But Carolco went belly-up and its library passed to MGM. Then Sony and Viacom, which had bought video and TV rights, respectively, lay claim to the franchise. The picture grew even murkier in 1998, when Marvel filed Chapter 11.

Then Marvel lawyer Carole Handler found a legal loophole: The original sale to Cannon hadn’t been registered with the U.S. Copyright Office, so rights reverted to Marvel.

Marvel then sold “Spider-Man” to Sony for close to $10 million and a small part of the gross.

It was a sweet deal. “Spider-Man” was out of development hell, and MGM and Viacom didn’t get a piece of the pic.

Compare that to pics like “The Grinch” and “Men In Black,” whose profits were split several ways. Even Harvey and Bob Weinstein managed to wrangle 5% of the first-dollar gross of “Lord of the Rings.” When the trilogy is complete, that could come to $50 million. Now that’s spider sense.

Follow @Variety on Twitter for breaking news, reviews and more