Fitch Ratings announced Wednesday it has downgraded Thailand’s largest industrial conglomerate Siam Cement Plc’s profit outlook from stable to negative.

The rating agency said the revision is base on SCP’s clouded outlook of weaker sales and higher raw materials plus energy costs—not mention to uncertain global demand in Portland cement.

Fitch said Siam Cement’s plan to invest 57 billion baht ($1.8 billion) in expanding its production capacity through 2010 has brought grim on its core businesses.

“The US recession has tumbled demand in petrochemical globally,” Fitch said. “This triggered fears on extended business downcycle.”