Russia's Rusal, the world's largest aluminum producer, said Thursday it has signed a landmark deal to restructure its $17 billion in debt, paving the way for a public offering this month.

A total of more than 70 lenders agreed to restructure some 50 credit agreements with Rusal to a maximum of seven years, indebted billionaire Oleg Deripaska's company said in a statement.

The deal includes the restructuring of a $7.4 billion debt to international lenders, $2.1 billion owed to Russian banks and $2.7 to Russian investment vehicle Onexim. It gives Rusal at most seven years to repay the debt.

Rusal has been locked in tough negotiations with foreign and Russian banks since last December, when it was hit hard by the global financial crisis. Rusal, one of the largest Russian companies remaining in private hands, was pressed for time to sign a deal because it hopes to go public at the Hong Kong stock exchange before the end of the year.

The deal "closes the chapter on a project of unprecedented size and complexity," Deripaska, Rusal's largest shareholder and chief executive, said in the statement.

Russia's richest man until last year, Deripaska is estimated by Forbes magazine to have lost some $24 billion of his fortune during the financial crisis because of high debt. Tumbling stock markets compelled him to cede stakes to creditors in several overseas companies, while at home his business empire -- which ranges from cars to metals to construction and bookstores -- struggles under the huge debt burden.

Under the deal with foreign lenders, Rusal will pay off its debt on a "pay-if-you-can" principle for the next four years, the company said. Over the following three years the remaining debt will be refinanced by current lenders, the company said.

As part of the deal with Onexim, Rusal said it has agreed to give a 6 percent stake to the investment vehicle owned by tycoon Mikhail Prokhorov as payment of $1.8 billion on its $2.7 billion debt.

Rusal said it would seek to repay $5 billion of its total debt by the end of 2013.