NEW YORK » The U.S. Department of Labor is investigating how RadioShack manages its retirement plan for employees, according to a regulatory filing.

The electronics retailer received a letter from the department saying that it was looking into its 401(k) plan going back to 2011, according to the filing with the U.S. Securities and Exchange Commission this week.

The Fort Worth, Texas, company is the target of at least three related lawsuits and said that it has provided documents at the Labor Department’s request. The agency conducted on-sight document reviews and interviews this month, it said.

RadioShack Corp. has struggled to compete as online retailers and it has fought with creditors who have opposed its plans to aggressively close stores to cut down on spending. The company said in November that it might need to file for Chapter 11 bankruptcy protection.

It recently brought on FTI Consulting as an adviser as it reported broadening third-quarter losses.