Troubled telecoms company Qwest Communications International, which faces a US criminal investigation into its accounts, may write-off a further $40.8bn (£26.2bn).

Qwest said it was cutting the value of assets including its fibre-optic and local telephone networks following the collapse of the telecoms bubble.

And it warned it might have to write-off further amounts.

The admission, after the close of trade on Wall Street came two days before Qwest was due to release its results.

An accounting scandal at the company caused auditor Arthur Andersen to resign, claimed the job of the company's chief executive and sent its shares plunging.

Shares in Qwest closed at $3.46, up 20 cents, or 6.1%, on the New York Stock Exchange on Monday but fell 18 cents in after hours trade.

The stock has fallen about 75% this year because investors are worried about its heavy debt load and declining sales.

Difficult call

Qwest also plans to restate $531m in revenues in 2000 and 2001 for improperly booked sales of capacity on its fibre-optic network.

The company accounted for the deals under methods approved by its former auditor Arthur Andersen but a review by its new auditor, KPMG, found discrepancies.

It has already restated $950m in revenues from its fibre-optic network last month.

Qwest has said it is looking at restructuring its $26.5bn of debt, but has no plans to file for bankruptcy.

The company, which is the dominant telephone operator in 14 US states, remains under investigation by the US Securities and Exchange Commission and Department of Justice.