Coors Light has passed Miller Lite to become the No. 3 bestselling beer in the U.S., behind Bud Light and Budweiser from Anheuser-Busch InBev. From a story in the Milwaukee Journal Sentinel:

Miller Lite’s sales last year totaled 17.7 million barrels, down from 18.35 million barrels in 2007, according to trade publication Beer Marketer’s Insights. Meanwhile, Coors Light’s sales increased 2.6%, to 17.75 million barrels compared to 17.3 million barrels.

Both Coors Light and Miller Lite fall under the umbrella of Chicago-based MillerCoors, the U.S. joint venture between SABMiller and Molson Coors that was formed last summer. Which makes this interesting, since these beers — traditionally rivals — are supposed to be complementing each other. Coors Light has been on a tear recently, possibly thanks to its clear marketing message that it is a really cold beer. Miller Lite, on the other hand, has been struggling.

When MillerCoors was formed, executives said the two beers could both grow, and that they wouldn’t just muscle each other out of the way. It’s not clear that hope is being fulfilled.