Whole Foods Market has expanded its two-hour delivery service to Amazon's main website, which offers free delivery to Prime members. The service has entered nearly 30 cities after a successful pilot in select markets including Denver and Portland, Ore.

Walmart is investing in artificial intelligence to more efficiently manage its stores and reduce costs. The retailer's Intelligent Retail Lab, located in a Long Island, N.Y., Neighborhood Market, includes thousands of cameras and shelf sensors to help employees quickly restock items and address problems such as spills.

Walmart has teamed with Postmates to offer same-day grocery delivery. The program kicks off in Charlotte, N.C., and will be offered in 100 other metro areas over the next few months.

Publix Super Markets has begun testing curbside pickup at two stores in the Tampa Bay, Fla., area, after discontinuing an earlier grocery e-commerce program that the retailer began testing as early as the 1990s. Publix, which offers grocery delivery through Instacart, will expand the new curbside pickup service to the Atlanta market by the end of 2017.

Albertsons will seek to raise about $100 million in an initial public offering, the retailer said in a regulatory filing Wednesday. The retailer, which acquired Safeway in a $9.4 billion deal earlier this year, is the second-largest grocer in the U.S. and operates 2,205 stores under the Albertsons, Safeway, Jewel-Osco, Acme and Tom Thumb banners.