Cub Foods recently laid off about 200 part-time workers in the Twin Cities, or about 3.5 percent of its workforce, in the latest possible sign of weakness for its struggling parent company, Eden Prairie-based Supervalu Inc.

Cub, the Twin Cities' largest grocery chain, made "staffing adjustments" that affected a small percentage of its workforce, said Mike Siemienas, a spokesman for Supervalu Inc. The "rightsizing" was intended to improve operating efficiency, he said.

Supervalu declined to be more specific about numbers. But officials for the two Twin Cities grocery workers union locals said about 200 part-timers were laid off in the past week and a half. About 150 were in the west metro and around 50 in the east metro. Cub employs about 5,500 people.

While winter is a traditionally slow time for the Twin Cities grocery business as snowbirds head south, traditional operators like Supervalu continue to be hurt around the country by a weak economy and fierce competition from discounters like Wal-Mart.

Supervalu has suffered more than most. Its fourth-quarter earnings came in well below Wall Street forecasts while same-store sales dropped for the 11th consecutive quarter.

The company said last month that an additional 350 corporate jobs will be eliminated by the end of May. The company had already shed 300 corporate jobs earlier in its fiscal year, making for about 10 percent of its nationwide corporate headcount.

Supervalu has also been retrenching at some of its chains, closing unprofitable stores and offering buyouts. And it noted that three of its East Coast chains -- Shaw's, Acme and Shoppers -- saw particularly weak sales during the past quarter.

Supervalu doesn't normally break out sales trends for Cub, but the chain is one of Supervalu's stronger ones in terms of local market share.

Mike Hughlett • 612-673-7003