A continuing slump in fertilizer sales has prompted Carr's Milling Industries to warn that 2009 profits will fall "appreciably lower" than last year's, sending its shares down more than 15%.

The UK agriculture and engineering group said it had suffered a "substantial" drop in fertilizer sales in the September-to-February half, with farmers relying on stockpiles and delaying new purchases.

The fall off had continued into the second half of its financial year, said the group, which typically views March and April as its strongest months for fertilizer sales.

"The fertilizer market has become more difficult in terms of both volumes and prices," Carr's said, adding that it expected fertilizer sales for the full year to show a "substantial adverse variance" to its internal forecasts.

Sales at its manufactured feed operations were also lower in the first half, thanks to competition from cheap cereal feed, although this business was trading satisfactorily in the second half, Carr's said.

Carr's shares closed down 47.5p, or 10.6%, at 402.5p in London after touching 381p earlier.

First half performance

Sales at the group's core Agriculture division rose 9.5% to £130.3m in the September-to-February half despite the slump in fertilizer sales, although its earnings fell 23% to £800,000.