NEW YORK—Wall Street closed mixed Friday after playing out a now familiar scenario: Upbeat sentiment about falling oil prices flagged amid ongoing concerns about weak credit markets and the economy. The major indexes also turned in a mixed performance after another volatile week.

Investors were encouraged early in the session as oil’s pullback lifted the outlook for consumer companies and eased concerns that record-high energy prices would force Americans to curb spending. Light, sweet crude dropped $1.24 to settle at $113.77 a barrel on the New York Mercantile Exchange, and earlie...