Chiron ( CHIR) swung to a fourth-quarter loss that reflected sharply lower sales due to the closing of its British flu vaccine factory in the third quarter.

The biotech lost $22.9 million, or 12 cents a share, in the quarter, compared with earnings of $121.8 million, or 61 cents a share, a year earlier. Revenue fell 23% from a year ago to $428.6 million.

On a pro forma basis that excludes amortization and other items, Chiron lost $7 million, or 4 cents a share, in the 2004 quarter. Analysts surveyed by Thomson First Call were expecting the company to earn 10 cents a share on that basis on sales of $439.6 million.

The stock fell $1.53, or 4.5%, to $32.41 after hours.

Chiron reiterated in its release that inspections of its Liverpool manufacturing facility in coming months by the U.K. Medicines and Healthcare Products Regulatory Agency and the Food and Drug Administration will determine if it is able to supply its Fluvirin vaccine next winter. The absence of Fluvirin sales in the most recent quarter was the reason for Chiron's year-over-year sales decline. It also cut gross margin to 47% in 2004 from 58% in 2003.

Chiron also reported higher expenses as a percentage of sales in the 2004 period, driven up by unfavorable foreign exchange rates and legal expenses related to the Liverpool shutdown. The company also cited "costs associated with the defense of the company's patents and technology, ongoing marketing and pre-launch programs, investment in geographic penetration, and corporate governance."

Among its bigger-selling products, Chiron's nucleic acid testing division posted revenue of $71.6 million in the 2004 quarter, while its pediatric vaccines had revenue of $57.7 million. Betaseron sales were $33.7 million in the quarter, while prleukin sales were $30.7 million.