Eddie Lampert will step down as chairman of Sears Holdings Corp.'s board, effective immediately, a company filing showed Thursday.

Lampert's resignation relates to the completion of the "going concern" transaction and is "not the result of any disagreement with the company on any matter relating to the company's operations, policies or practices," according to the filing.

ESL Investments, Lampert's hedge fund, won a bankruptcy auction last month to buy the once iconic U.S. retailer after presenting an improved offer of $5.2 billion.

Lampert, who stepped down as chief executive officer of the company when it filed for bankruptcy last year, had earlier said he would hire a new chief to lead the company.

Kunal Kamlani - president of ESL Investments - also stepped down from the board, the company said.