PARSIPPANY, N.J. (AP) ¿ GenTek Inc., which makes chemical and industrial products, said Friday an impairment charge drove the company to a net loss in the fourth quarter. The company said it lost $126 million, or $12.63 a share, in the quarter ended Dec. 31 compared with a profit of $18.8 million, or $1.64 a share, a year earlier. Sales improved slightly to $139.1 million, up from $134 million in the same quarter a year ago. The company said it recorded a $157 million restructuring and impairment charge. For the year, the company said it lost $109 million, or $10.83 per share, compared with a profit of $29.8 million, or $2.57 a share, the year before. The 2008 results included a non-cash impairment charge related to the goodwill and intangible assets of the valve actuation systems segment of $156.5 million. The charge represents the write-off of the entire goodwill balance and nearly all of the intangible assets related to the valve actuation systems segment, which were originally recognized upon the company's emergence from bankruptcy in 2003.