NEW YORK (Bloomberg) ? Shares of Global Crossing Ltd., the fiber-optic network operator that exited bankruptcy in December, fell as much as 36 percent after Grant Thornton LLP withdrew its audits for the past three years.

Global Crossing shares tumbled $2.85 to $7.15 at 4 p.m. New York time in Nasdaq Stock Market composite trading. Earlier the shares fell as low as $6.40. The stock has fallen 77 percent this year.

?Their former auditors have refused to stand by their audits. They have no financials, and that?s putting a lot of pressure on the stock,? said Igor Volshteyn, an analyst at Tejas Securities Group Inc. in Austin, Texas who has a ?speculative buy? rating on Global Crossing shares and owns them.

Grant Thornton had to withdraw its audits because Global Crossing said its financial information could no long be relied on, general counsel Margaret Zagel said.

?If the company can?t stand behind its financial statements, we cannot leave an opinion out there,? she said in an interview.

Without audited financial results, the shares are likely to be de-listed from Nasdaq, Volshteyn said. Global Crossing shares were previously de-listed from the New York Stock Exchange in January 2002 after the company filed for bankruptcy protection.

Global Crossing disclosed Grant Thornton?s move in a filing yesterday with the U.S. Securities and Exchange Commission.

Bermuda-based Global Crossing surprised investors Tuesday by saying it will restate 2003 results after underestimating some liabilities. The restatement, which is tied to money Global Crossing may owe other carriers to use their networks, is the latest misstep for the company, which is under investigation by U.S. regulators for a separate accounting matter.

The company, run by Chief Executive John Legere since October 2001, has forecast a sales decline for 2004.

This month it fired Grant Thornton and hired Ernst & Young LLP as auditor.

Global Crossing, which ex-Chairman Gary Winnick founded in 1997, sought Chapter 11 protection in January 2002 after prices for network services tumbled. Winnick stepped down as chairman later that year.

The case was the second-biggest telecommunications bankruptcy, after WorldCom Inc., which filed for creditor protection in July 2002 and emerged this month.