ISTANBUL, Nov 6 (Reuters) - Turkish polyester yarn and fibre producer Sonmez Filament has halted output permanently as the global crisis worsens market conditions, the company said on Thursday November 4th.

The move reflects a sharp slowdown in the Turkish economy this year as worldwide financial turmoil bites. Turkey's major textile sector, a key exporter, has also been hit by waning foreign demand.

Shares were down 1.85 percent at 0.53 lira on Thursday before they were suspended at 0815 GMT ahead of the announcement.

Sonmez Filament, active since 1972 and based in the western Turkish city of Bursa, had temporarily halted production in August citing negative market conditions.

"Since then no improvement in the negative market conditions has been registered and the impact of the global crisis has increased market uncertainty further," the company said.

It also cited rises in electricity and gas prices, delays in receiving payments and increases in low-cost imports as reasons for the move. The company, part of the Sonmez Holding industrial group, had been operating at a loss since 2003 and said measures to cut capacity and increase productivity had not enabled it to rebound.

It had sales of 52.1 million lira ($34 million) in 2007 and an operating loss of 2.25 million lira.

(Reporting by Daren Butler; Editing by Mike Nesbit and Sharon Lindores)