It may qualify as the least surprising biotech news of the new year, but Chiron ( CHIR) failed to get its NAT blood-testing system approved by U.S. drug regulators by Dec. 31. The Emeryville, Calif.-based biopharmaceutical firm had told investors and Wall Street analysts to expect Food and Drug Administration approval of the NAT blood test by the end of 2001. TheStreet.com cast significant doubt on that prediction in late November, when a top U.S. blood-banking official said the heft of the approval application would keep the FDA busy until the middle of 2002. In December, two Wall Street analysts joined the ranks of those believing NAT was delayed, lowering 2002 earnings estimates for Chiron as a result. Despite missing its self-imposed deadline for NAT approval, Chiron has yet to issue a statement as to what went wrong or to say whether it has a new timetable for approval. Chiron executives would not return calls seeking comment. The NAT blood-testing system, also known by the brand name Procleix, is designed to detect the presence of antigens such as HIV and hepatitis C in donated blood much earlier than current tests. NAT is Chiron's biggest potential growth driver, especially after the failure in November of its experimental sepsis drug. So, a long delay in the blood test's approval could force Chiron to reduce revenue and earnings estimates for the year. Wall Street's view of Chiron's 2002 earnings outlook is already weakening, with consensus estimates dropping a penny to $1.15 per share, according to Thomson Financial/First Call. Chiron closed out 2001 at $43.84 per share, a 1.5% drop for the year. Chiron shares closed Friday at $44.72.