Weak demand, higher crude prices hit Valero with losses in 4Q, full-yearValero Energy Corp. said Wednesday it lost almost $2 billion in 2009 as the company shuttered a Delaware refinery and struggled to pass higher oil prices along to consumers.Much of ...

Chevron shares fall following warning of second quarter weaknessShares of Chevron Corp. slid on Friday a day after the company warned of weak second-quarter results, hurt by lower refining margins in the U.S. and foreign currency losses.Chevron's stock fell ...