J.C. Penney Co. Chairman Thomas Engibous affirmed his support for Chief Executive Myron Ullman, saying he has led “significant actions to correct the errors of previous management” since he retook the helm of the struggling department-store retailer.

The statement came after CNBC disclosed that Bill Ackman, head of the investment firm Pershing Square Capital Management, L.P. and a J. C. Penney director, sent a letter to the company's board to have a new CEO named in 30 to 45 days. Ackman also told fellow Penney board members that Allen Questrom, a former Penney CEO, would return as chairman if the department store operator chose a new CEO he liked.

According to the New York Post, insiders said the board has lately discussed two top candidates: Foot Locker CEO Ken Hicks, a former Penney executive, and Brendan Hoffman, CEO of the Bon-Ton.

Addressing the letter in a statement, Engibous said that since taking over as interim CEO four months ago, Ullman “has led significant actions to correct the errors of previous management and to return the company to sustainable, profitable growth.”

The effort has included stabilizing the organization, improving the company's financial position, bringing inventory back to appropriate levels, and restoring successful private brands.

Engibous continued, “When Mike returned, it was understood that there would be an effort to rebuild the management team, including a search process to identify his successor. The CEO search process, which began in earnest three weeks ago, will be careful and deliberate to ensure we find the right long-term leader for jcpenney. In the meantime, Mike and the leadership team will continue the work under way to improve the company's performance and get back on a path to profitable growth.”

Engibous concluded, “The Board of Directors strongly disagrees with Mr. Ackman and is extremely disappointed that his letter was released to the media at the same time that it was sent to the Board. Mr. Ackman has been integrally involved in the Board's activities since he joined two years ago. This includes leading a campaign to appoint the company's previous CEO, under whose leadership performance deteriorated precipitously. His latest actions are disruptive and counterproductive at an important stage in the company's recovery.”