The expected average growth for the next five-year period is less than half the average growth of 26.3 percent seen in the five years to 2003. It is also lower than the previous five year 2003-2007 forecast for 11.2 percent growth.

This year, installation of wind power is expected to decline four percent from last year's installed 8,344 megawatts (MW).

Looking beyond 2008, BTM said it expected wind power to grow by 25,000 MW per year, bringing the total industry to 194,000 MW.

"Offshore development in Europe will take off in large scale from 2007, particularly in Germany and Britain. The U.S. forecast is uncertain and dependent on the extension of the Production Tax Credit as well as other drivers," BTW said in a statement.

BTM said a record 8,344 MW were installed worldwide in 2003, taking the total wind power past 40,000 MW, enough to power more than 16 million average European homes.

Europe is still the driving force in the wind power industry accounting for 66.5 percent of global installed MW in 2003. Germany remained the single largest market in the world, although growth dropped to 17 percent from 37.4 percent last year.

The U.S. market grew slightly more than expected to 1,687 MW after a slow 2002. Its growth has been held back due to the uncertain status of the wind energy production tax credit (PTC), a key federal tax incentive to promote wind power.

The world's five biggest wind turbine makers account for 76 percent of the global market, according to 2003 data.

Denmark's Vestas (VWS.CO: Quote, Profile, Research) lost half a percentage point of the world market but remained No. 1 with a share of 21.7 percent, while GE Wind, a part of General Electric (GE.N: Quote, Profile, Research) , boomed to 18 percent from 8.8 percent.

Germany's privately owned Enercon lost market shares to hold 14.6 percent, as did Denmark's NEG Micon (NEG.CO: Quote, Profile, Research) , coming in fifth with 10.2 percent.