Unocal Corp. said its Union Oil Co....

Unocal Corp. said its Union Oil Co. of California subsidiary completed a $500-million deal to form a 50-50 joint venture with the national oil company of Venezuela to take over Unocal’s Illinois refinery, service stations and other assets in the Midwest . . . Deloitte Haskins & Sells and Touche Ross, two of the country’s biggest accounting firms, completed a merger of their U.S. operations into a company called Deloitte & Touche . . . The number of working U.S. oil and gas rigs reversed a two-week slide with sharp increases in Texas and Oklahoma to total 1,062, up 25 from a week ago, according to a report by Baker Hughes Inc., Houston.