Siam Cement PCL (SCC), Thailand’s biggest industrial conglomerate, reported a worse-than-expected 21 per cent fall in quarterly net profit on Wednesday as a weak economy undermined cement demand.

Siam Cement’s near-term outlook is weak due to declining cement demand and a flood of new supply from petrochemical plants from 2009, analysts said.

The Bank of Thailand cut its 2008 economic growth forecast last week to a 4.3-5 per cent range from 4.8-5.8 per cent, citing the impact of the global credit crisis and political unrest at home. For 2009 it forecast 3.8- 5 per cent.

SCC, which earns up to half of its profits from petrochemicals, reported its July-September profit fell to THB5.94bn from THB7.55bn a year before, when it booked a THB1.9bn special gain, mainly from the sale of a stake in petrochemical producer Aromatics.

It had no one-off gains in the third quarter this time.