Acquisition-Related Costs Add to Affymetrix Loss

Santa Clara-Affymetrix Inc. said its fourth-quarter loss widened because of acquisition- related costs even as the biotechnology company sold more of its GeneChip genetic-research tools.

Affymetrix lost $21.5 million, or 38 cents, compared with $5.5 million, or 10 cents, in the quarter a year earlier. Revenue rose 70%, to $59.4 million from $34.9 million. Before the acquisition-related costs, the company’s loss was smaller than analysts had expected, sending shares higher in after-market trading.

Santa Clara-based Affymetrix dominates the market for gene chips, which are slides with millions of genetic fragments attached. The company’s products are increasingly in demand as companies race to use data gathered from the recent mapping of the human genome to develop drugs.

“The market is still growing, and their dominance is still intact,” said Scott Greenstone, analyst at Thomas Weisel Partners.

The earnings were released after the close of U.S. markets. In late trading, Affymetrix shares rose as high as $66.88. The shares fell $1.56 to $61.44 today. In the past 12 months, Affymetrix shares have lost about half their value.

Affymetrix also made a $3.5-million payment in the quarter for its sponsorship of the public mouse genome sequencing effort.