Stocks in the consumer sector were mostly lower even after the University of Michigan said a preliminary reading showed consumer sentiment improving more than expected. A rebound in fuel prices is seen pressuring retail spending.

Walmart is shuffling the leadership atop its massive U.S. business as the retailer's new chief executive continues to build his team. Kieran Shanahan, chief operating officer for Walmart U.S., will leave the role this week, the company said in an internal memo viewed by The Wall Street Journal. Shanahan, 45 years old, will be succeeded by Kyle Kinnard, currently COO for Walmart International.

Produce supplier Taylor Fresh Foods said it was voluntarily removing all of the company's iceberg lettuce sourced from central Mexico from the U.S. market, after the Food and Drug Administration traced a parasitic outbreak to shredded lettuce produced in the country.

Nike ran low on U.S. soccer jerseys at the worst possible time. Now they are restocked, too late to capitalize on the team's run through the World Cup.

Write to Paulo Trevisani at paulo.trevisani@wsj.com