Kohl's Corp.'s chief merchandising officer is leaving the retailer amid the company's efforts to improve sales.

The Menomonee Falls, Wis.-based business said in a regulatory filing that Donald Brennan resigned from his position Monday. Brennan, who has been with Kohl's since 2001, will leave the company April 1.

Kohl's did not respond to a request Tuesday for comment on the reason behind his departure.

The company has been dealing with sluggish sales for some time despite its efforts to draw more customers, including the introduction of several new brands in recent years, such as Jennifer Lopez and Rock & Republic.

The board gave Brennan an "inconsistent" rating for his performance in 2012 and 2013.

Kohl's profit fell nearly 10% for its last fiscal year to $889 million, or $4.05 per share. Its annual revenue dipped 1% to $19.03 billion. And sales at its stores open at least a year fell 1.2%, which is considered a key indicator of financial performance as it strips away the impact of recently opened and closed stores.

Brennan's resignation follows the departure of John Worthington, its chief administrative officer, in June last year.

Kohl's has also brought on new leadership recently to help fuel growth at the company. It hired Michelle Gass, a former Starbucks Corp. leader, to join the retailer in June in the newly created position of chief customer officer.

The retailer said in the regulatory filing that it will pay Brennan a severance payment of 2.9 times his current annual salary, plus the average of incentive pay over the past three years. Based on his 2013 salary of $927,200 and incentive payments, that would total roughly $3.2 million.

He will also receive a partial bonus in 2015 based on the company's performance in 2014.