The global market for large motors and generators grew by 11% during 2005 to reach a combined value of $1.6bn. The average growth rate for this mature market, is usually 2-3% a year, says the market researcher, IMS, which published the figures.

But the rapid growth in sales has been tempered by the dramatic increases in the cost of raw materials, such as copper, which has meant that margins are being squeezed. "Motors require a lot of copper," points out IMS analyst, Steve Odom. "While average selling prices of these machines stayed relatively stable in 2005, prices for copper increased 45% in 2005, and 75% in the first seven months of 2006."

Part of the growth has come from developing countries, which are using large machines increasingly in applications such as mining, oil and gas production, power generation and water treatment.