Henry Cavill's Superman will be the first big screen version not to sport the trunks. Both Christopher Reeve and Brandon Routh's Superman movies carried over the character's red underpants from the comic book.
Watchmen filmmaker Snyder told the New York Post of the costume alteration: "[It] was a big deal for me, and we played around for a long time.
"I tried like crazy to keep the red briefs on him. Everyone else said, 'You can't have the briefs on him'. I looked at probably 1,500 versions of the costumes with the briefs on."
He continued: "If you look at the costume, it's very modern, but the relationship to the original costume is strong.
"You come onto a project like this, and you hear about modernisation and you hear about bringing things forward to today, and all you can do is hope that it's going to look cool and different from anything you've seen before."
A new trailer for Man of Steel will debut in front of The Hobbit: An Unexpected Journey next month.
Man of Steel, also starring Amy Adams, Russell Crowe, Kevin Costner, Diane Lane and Laurence Fishburne, will open in cinemas on June 14, 2013.
Watch the Man of Steel teaser trailer below: