Monthly supply-demand estimates showing a largely unexpected cut in US 2017-18 exports and a buildup in world ending stocks outside China helped set the stage for a marketing week sell-off in cotton futures.

July lost 464 points for the week ended Thursday to close at 71.91 cents, its lowest close since December 30. December shed 363 points to settle at 69.47 cents, its lowest finish since December 28.

The market lost ground across the board five sessions in a row. July has closed on the plus side only once in the last ten sessions, while December has finished lower in five of the last six calendar weeks.

Disappointing US weekly export sales, with old-crop upland sales slowing to the second lowest of the marketing year, helped to keep the market in a steep downtrend.

US all-cotton export sales for shipment this season came in below expectations. Commitments held a lead of about 63 per cent over cumulative sales a year ago. The forecast is for exports to reach the second largest on record, up 58 per cent from last season.

Commitments stand at 103 per cent of the export forecast, compared with 101 per cent of final shipments at the corresponding point last season. Some of the 2016-17 commitments will be used to help meet domestic mill and export needs through about the first three months of the 2017-18 marketing year ahead of volume movement of the new crop.