(Reuters) - Kohl's removed Ashley Buchanan as CEO following an investigation that uncovered company policy violations by the chief executive, the department store chain said on Thursday.

The move comes after Buchanan was appointed to the top job in November, replacing Tom Kingsbury.

A board investigation found Buchanan directed the company to engage in vendor transactions that involved undisclosed conflicts of interest, Kohl's said, adding that Buchanan's removal did not affect its financial reporting or other employees.

The department store chain named Michael Bender as its interim CEO, effective immediately, and said it would begin a search for a permanent chief executive.

Kohl's also provided preliminary first-quarter results, with the company expected to report earnings on May 29.

The company has been grappling with weak demand for several quarters as department stores struggle to attract consumers due to stiff competition from e-commerce firms and big-box retailers such as Walmart and Costco.

Kohl's expects first-quarter comparable sales to fall between 4.3% and 4%, compared with analysts' average expectation of a 6.34% decrease, according to data compiled by LSEG.

The company expects a loss per share in the range of 24 cents to 20 cents, compared with estimates of a loss of 52 cents.

Kohl's shares, which have fallen 52% so far this year, rose 7%.