Mel Gibson Tires of Eco-Lawsuit and Settles Up

Things are rubber ducky for Mel Gibson ... we've learned he just settled a bitter lawsuit over recyclable tires.

Gibson was sued by a dude who claims -- at the behest of Mel -- he invested his life savings in a company called Green Rubber, which developed technology to devulcanize rubber so old tires could be recycled.

Nader Sherif claimed Mel promised the guy could sell his stock back to the company at any time and get his money back, and he further claimed Mel promised to personally write him a check if the Green Rubber refused. Yes, you guessed it. Sherif wanted his jack back, the company refused and Mel told him to pound sand.

Sources tell TMZ ... Mel paid Sherif something, but we don't know exactly how much.