The total revenues of PPG Industries increased by 4 percent to $3.2 billion for the fourth quarter, but those of its optical and specialty materials unit were down by 2 percent to $239 million. The optical business alone, which includes optical monomers and Transitions Optical, had a mid-single-digit increase in volume, growing in all regions.

For the whole company, net income was $71 million, a huge drop of 65 percent from the same period last year. Earnings in the optical and specialty division fell by 28 percent to $33 million, which the company attributed to lower volumes of silicas and higher costs for selling and marketing that stemmed from the increase in the volume of optical products sold.

For all of 2008, sales for PPG were $15.8 billion, up by 29.7 percent from 2007. Earnings fell by 35.5 percent to $538 million. Full-year revenues for the optical and specialty segment increased by 10.2 percent to $1.13 billion, with earnings in that division climbing by 3.8 percent to $244 million.