The dismal start for US winter wheat seedlings has worsened the country's export prospects by threatening a rise in domestic prices and handing competitiveness to rival shippers, US farm officials said.

The US Department of Agriculture, expanding on a decision on Tuesday to downgrade hopes for American wheat exports in 2012-13, said that prospects for shipments "continue to decline".

"Even though it has been expected that US wheat exports will be back-loaded, with more exports occurring in the later part of the [marketing] year when the main competitors exhaust their supplies, the current US pace of exports is extremely poor," the USDA said.

"Already, five months into the international marketing year, it is getting increasingly difficult to achieve projected exports, especially with larger wheat supplies and stronger competition from Australia and Canada."

'Increasingly uncertain'

From July to the end of November, exports appeared to be tracking 10% lower than a year before, when comparing the sum of shipment data and unfulfilled sales.

And the poor start to the 2013 US winter wheat crop, which has entered dormancy in its worst condition on record, has exacerbated the threats to export hopes.

"The outlook for next year's US wheat crop has grown increasingly uncertain, given unfavourable November crop conditions," the USDA said.

If a "pessimistic outlook" for the crop was realised, "wheat prices could rise more than would be expected seasonally", with an impact on export competitiveness.

Historical pattern

The USDA on Tuesday, in its benchmark Wasde crop report, cut by 50m bushels (1.4m tonnes) to 1.05bn bushels (28.6m tonnes) its estimate for US wheat exports, a revision blamed for a drop in wheat prices to a succession of five-month lows.

At Texas A&M University, farm economist Mark Welch said that while wheat exports were now on a "straight-line trajectory" to meet the USDA's 2012-13 projections, meaning the weekly pace was on target, normally shipments were quicker earlier in the season.

"Usually we have reached 70% of the marketing-year export projection by the end of November compared to 58% this season," Dr Welch said.

Chicago wheat futures for March stood up 0.3% at $8.10 ¾ a bushel at 10:40 UK time (04:40 Chicago time), on track for their first gain in six sessions.