Frontline (NYSE:FRO) shares collapse in Oslo as the world's largest operator of oil tankers, worried it will run out of cash next year, pursues talks with lenders. Down 60% since 2010's start, tanker rates have been in unprofitable territory for nearly all of 2011. Frontline is trying to get in front of other shippers that will likely need restructuring in 2012. Shares -42% premarket.