J.C. Penney Co. said Monday that it is selling the bulk of its interest in mall developer Simon Property Group Inc. for $248 million as it focuses on its core business.

The Plano, Texas, company said the sale announced Monday was the first step in a plan, put in place last year, to sell off assets that don't make up the crux of its department store business. J.C. Penney also said the move bolstered its balance sheet.

Under a new CEO, former Apple Inc. executive Ron Johnson, J.C. Penney is overhauling every aspect of its business from its pricing to the brands it carries. But some investors have concerns about the company's ability to turn its business around as sales trends deteriorate.

J.C. Penney said that Indianapolis-based Simon redeemed 2 million units of limited partnership interests from the department store chain for $248 million. JCP Realty, a unit of J.C. Penney, kept about 205,000 limited partnership units.

J.C. Penney received the units at the time of Simon's initial public offering in 1993 as part of joint-venture investments the companies made together in several shopping malls.