Wal-Mart Stores Inc. plans to open its first Walmart Express store on Chicago’s South Side.

The 10,000-square-foot store is set to open this summer in the Chatham Market on 83^rd Street, said a source familiar with the plans.

Crain’s Real Estate Daily broke the story on Wednesday.

Chatham’s express store will be near a 150,000-square-foot Walmart Supercenter, which is set to open at the end of 2012, and will allow Walmart to tap into people’s wallets sooner.

“This small store will provide affordable groceries more quickly,” the source said.

The company announced the concept — small stores for rural and urban locations — during an analysts call in February. The stores would be even smaller than the company’s Neighborhood Market stores, which are usually 40,000 square feet and have been around since 1998.

The Tribune reported last month about Walmart’s plan to open a Neighborhood Market store at the Presidential Towers.

Walmart is shifting emphasis away from its sprawling Supercenters to smaller stores to reverse a decline in U.S. sales at stores that have been open for at least a year, a key metric of retail health.

“We will move forward with even greater urgency in opening small stores,” said Mike Duke, Wal-mart’s president and CEO at last month’s call with analysts.