LONDON (AP) _ Producer prices have registered their largest annual fall since records began in 1958, largely due to plummeting prices of petroleum products, according to government figures published Monday.

The output producer price index for domestic sales of manufactured goods _ an indicator of producer prices _ decreased by 1 percent in the 12 months to November, compared with a fall of 0.6 percent in the year to October, according to the Office for National Statistics. November producer prices were down 0.4 percent from October.

Petroleum product prices collapsed 15.1 percent over the year to November, the largest annual drop since December 1986, the figures showed. Between October and November, they fell by 4.1 percent. Crude oil prices are now 40.4 percent below their November 2000 level.

The Office for National Statistics said manufacturers are finding it difficult to raise prices in the face of stiff competition from abroad, while the comparative weakness of the European single currency makes British imports expensive for countries in the euro zone.

A slight rise in food prices in November, mainly for lamb and grain mill products, helped to offset the drop in producer prices slightly.

Input prices _ the cost to manufacturers of raw materials and fuel _ rose by 0.1 percent between October and November, although the cost of imported materials, including oil, declined by 0.8 percent.