The office rental firm Regus has filed for chapter 11 bankruptcy protection in the United States for the US part of it business.

The company, which supplies fully equipped office space, grew rapidly in the boom years of the late 1990s.

But the economic downturn caused rates to drop and left the company with vacant offices.

"Essentially the US was the major loss-maker in the group and by filing for chapter 11 we have staunched the losses," chief executive Mark Dixon told BBC News.

"The business climate in the US has become more difficult over the past year and we have decided to use chapter 11 protection to reorganise our business there."

Rebuilding the company

The company said that in recent months it had tried to restructure the terms of its leases with US landlords.

But when the two sides could not agree a settlement, Regus decided to file for bankruptcy protection.

"Regus is wholly committed to its global strategy in which the US market is a key component.

"Our clear objective is to return our US business to profitability and chapter 11 is now the quickest and most reliable route to secure this," Mr Dixon said.

In December Regus raised up to �57m ($91m) by selling part of its UK business and it will be using that money to help pay to rebuild the US side of the firm.