UPDATE 2-Australia's Boral cuts f'cast on US housing downturn

(Adds analyst comment, updates shares)

MELBOURNE, May 8 (Reuters) - Australian building materials maker Boral Ltd (BLD.AX: Quote, Profile, Research, Stock Buzz) cut its full-year profit forecast on Thursday due to the deterioration in U.S. home-building, sending its shares down 5 percent.

It now expects profits in the year to June 2008 to fall about 20 percent from last year, rather than the 15 percent it forecast in February.

Boral said in a statement that profit after tax would be at the bottom end of market forecasts of between A$234 million ($221 million) and A$256 million.

"Clearly U.S. housing hasn't reached the bottom yet," said Scott Marshall, head of industrials research for Shaw Stockbroking.

"You'd have to assume there remains risk for Boral's operations in the United States."

Boral said annualised U.S. housing starts in the March quarter were about 25 percent weaker than in the December half, and there was no sign of the normal spring recovery.

"The second-half result for the U.S. business will be significantly lower than in the first half," Boral said.

It said it would cut production at its bricks and roof tile plants, with brick output to be about 40 percent lower than in the first half.