Paul G. Woollatt resigned Friday as chief operating officer of Downey Financial Corp. and its subsidiary, Downey Savings & Loan. Woollatt, 50, declined to elaborate on his departure from the Newport Beach company except to say it was on good terms. Calling Downey "well positioned to prosper," he expressed pride at his work there and said he is "looking forward to new challenges and other opportunities" in financial services. Woollatt joined Downey in 1979 but left in 1990 to help rescue troubled First Western Bank in Las Vegas. After First Western was sold to Norwest Corp., he returned to Downey in 1995 as director of retail banking. He became chief operating officer in 1998, replacing Daniel Rosenthal, who was promoted to chief executive. Downey has assets of $10.9 billion and operates 117 branches in California.