DENVER BUSINESS JOURNAL — A fight over the "Keystone" beer brand name took a turn for the nasty.

In February, Stone Brewing Co. of Escondido, California, sued MillerCoors, a unit of Denver-based Molson Coors Brewing Company (NYSE: TAP) in a California court, claiming the marketing of Keystone beer — specifically referring to the product as 'Stone' — is confusing.

Last week, MillerCoors fired back against the smaller brewery in an 82-page rebuttal of the suit, calling the lawsuit "meritless."

"Stone Brewing’s claims are misleading and ultimately meritless when Stone Brewing’s rhetoric is separated from the facts. Stone Brewing’s complaint makes grandiose allegations, but leaves out most of the facts relevant to this dispute," according to MillerCoors' response.

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