Siam Cement Plc posted a 29 per cent increase in fourth-quarter net profit as better earnings from its chemical unit outweighed weakness in cement and the building materials business.

For 2015 Thailand's largest industrial conglomerate posted a 35 per cent rise in net profit of THB45.4bn (US$1.27bn) due to strong chemical earnings, while its sales fell 10 per cent to THB439.6bn due to lower chemical prices, it said in a statement.

Last week Bualuang Securities cautioned that the Cement-Building Materials' (CBM) division is expected to come under pressure from depreciation expenses related to ASEAN cement plants and weaker consumption in its home market of Thailand. The CBM division is expected to have posted "limp" results in the final three months of 2015. "Increasing cement usage from the government sector alone was unable to push overall domestic demand back to growth in 4Q15," Bualuang wrote.