STATS ChipPAC, a semiconductor test and packaging service provider, now expects its third-quarter sales to decrease 3-5% on quarter. The firm previously estimated flat sequential growth.

STATS ChipPAC attributed the guidance cut to "weakness in the PC end market and delays in the supply of advanced silicon node wafers for high-end smartphones."

STATS ChipPAC also cut its capex outlook for the third quarter to US$160-170 million from the US$170-190 million predicted previously. Its EBITDA guidance for the quarter remains unchanged at 21-23%.

STATS ChipPAC CEO Tan Lay Koon remarked during a conference call in July that demand for advanced packaging and test turnkey services for customers in the high-end smartphone market is anticipated to rise later in 2012.

Market sources have speculated that STATS ChipPAC along with Advanced Semiconductor Engineering (ASE) and Amkor Technology provide backend services for Qualcomm's 28nm Snapdragon S4 chips. Qualcomm is set to significantly raise wafer starts for the baseband chips at Taiwan Semiconductor Manufacturing Company (TSMC) starting mid-September, said the sources, adding that the three backend houses will enjoy substantial revenue growth in the fourth quarter.