Shares of mall companies slumped after Sears Holdings Corp. announced plans to shutter 150 stores as part of an effort to turn around the ailing chain.

A Bloomberg index of regional-mall landlords fell as much as 2.8 percent, the largest drop in almost two months. CBL & Associates Properties Inc. had the biggest decline among companies in the index, falling as much as 4.1 percent, and Simon Property Group Inc., the largest U.S. mall owner, dropped as much as 3.2 percent. By comparison, the broader Bloomberg real estate investment trust index, which also includes companies that own properties such as office buildings and hotels, was little changed.

The move by Sears is the latest sign that many retailers are losing ground in the battle to retain shoppers that are increasingly turning to the internet. Macy’s Inc., the largest U.S. department-store chain, yesterday cut its earnings outlook and said it would eliminate 6,200 jobs, and Kohl’s Corp. said holiday-season sales dropped more than it expected, leading it to cut its fiscal 2016 earnings forecast.

Shares of mall owners tend to be hurt by bad news from struggling retailers, said Alexander Goldfarb, an analyst at Sandler O’Neill & Partners LP. Still, the best properties are insulated from problems plaguing department stores as landlords add restaurants and other higher-quality tenants to replace failing merchants, he said.

The stock selloff “is a knee jerk,” Goldfarb said in an interview. “I don’t think anybody is surprised that some department store chains are having challenges. Some retailers are having challenges, and others are doing well.”