BENICIA -- Rumors are swirling that Valero is putting its two California oil refineries on the market, including one in Benicia that is the city's largest employer. The speculation follows a Wall Street Journal report last week that said the San Antonio-based company has enlisted Citigroup Inc. to help find a buyer for the facilities. The article cited unnamed sources familiar with the matter. Valero operates a 78,000-barrel-a-day refinery in Wilmington outside Los Angeles and a 132,000-barrel-a-day refinery in Benicia. Together, the plants represent about 10 percent of the company's U.S. refining capacity. Valero, which has been critical of California's...