NEW YORK — Time is running out for Sears, the retailer’s largest investor and chief executive warned Monday.

With the company facing a large loan payment due next month, Edward Lampert, who serves as both Sears’ CEO and its most influential shareholder and lender, said it needed to drastically restructure its debts to avoid “alternatives.”

Those alternatives include bankruptcy.

Lampert’s hedge fund, ESL Investments, has proposed a series of deals that would reduce the retailer’s $5.6 billion debt load. They include selling off many of its remaining stores and asking lenders to exchange their loans for equity stakes in the beleaguered company.

ESL’s proposal, outlined in a securities filing Monday, amounts to a wholesale financial restructuring of Sears outside a Chapter 11 bankruptcy filing.

If it is enacted, Sears’ debt would fall to about $1.2 billion, freeing up cash to be reinvested in its struggling retail operations.

While Sears has been troubled for years, ESL’s proposal signals an increased urgency from Lampert. His firm is warning that Sears now faces “significant near-term liquidity constraints,” with $134 million in debt coming due in a few weeks.

It was not clear whether lenders would accept an offer to take an equity stake in the company because it is premised on a belief that Sears has a future in retailing. Analysts say that is far from certain, as Sears keeps losing money and customers to more nimble and digitally adept competitors.

The latest rescue attempt is also complicated because ESL is controlled by Lampert, who has an unusual role at Sears. He is its chief executive and chairman, and in addition to being the largest shareholder, his hedge fund also holds roughly 40 percent of Sears’s debt. This gives him claim on a great deal of the company’s assets, particularly its real estate.

Real estate is a key component of Lampert’s latest idea. He proposes that Sears’ lenders — whose loans are secured by the company’s stores — stop collecting interest for a year while the company tries to sell those stores.

After a year, if Sears fails to sell enough stores to pay off $1.4 billion in debt, then it will sell the stores to the lenders for a price equal to the value of their debt.