Genzyme Corp said on Tuesday its preliminary fourth-quarter revenue fell as a manufacturing crisis led to a shortage of two key drugs.

Total fourth-quarter revenue fell to $1.08 billion, down from $1.17 billion in the year-ago quarter and in line with the average forecast from analysts polled by Thomson Reuters I/B/E/S.

For the full year, revenue slipped to $4.5 billion from $4.6 billion in 2008.

The company released the unaudited data at the J.P. Morgan healthcare conference. It will provide full financial results and a 2010 outlook on February 17.

Sales of Cerezyme, the company's top-selling drug for Gaucher disease, and the one most affected by the manufacturing crisis, fell to $106 million in the fourth quarter, down from $306 million in the year-ago period.

Full year sales of Cerezyme were $793 million, down from $1.2 billion in 2008.

The company began shipping new product in November and patients are expected to be able to resume normal dosing schedules in the first quarter.

We are managing through the supply interruption, getting beyond it, and moving into a period of recovery, said Henri Termeer, the company's chief executive, in a statement. We are fundamentally strengthening the company.

Sales of Fabrazyme -- the company's treatment for Fabry disease, which was also affected by the plant closure -- were $59 million in the fourth quarter, versus $126 million a year before.

Full-year Fabrazyme sales were $431 million, down from $494 million in 2008.

Genzyme said it began shipping newly produced Fabrazyme this week. It is currently producing at a rate that meets 70 percent of demand, and said it hopes to begin shipping Fabrazyme at a rate that will meet between 70 and 100 percent of demand in the second quarter.

Genzyme said it plans to conduct a post-marketing study of Fabrazyme exploring lower dosing options for patients in the earlier stages of the disease.

INVESTMENTS ACROSS THE BOARD

Termeer said Genzyme is making investments across all areas of its genetic disease business, which includes Cerezyme and Fabrazyme, including increasing its sales force, adding manufacturing capacity, and building its product pipeline.

Activist investor Carl Icahn is considering launching a proxy battle for Genzyme but Termeer has said he would not be interested in coming to a collaborative agreement with Icahn.

He said on Tuesday he has had no contact with Icahn.

Sales of Myozyme, the company's treatment for Pompe disease, rose to $92 million in the fourth-quarter, up from $75 million in the year-ago period.

Total 2009 Myozyme sales were $324 million, up from $296 million in 2008.

Sales of Renagel and Renvela, treatments for kidney disease, were $179 million in the fourth quarter, up from $169 million in the fourth quarter of 2008.

Full-year sales of the kidney drugs were $707 million in 2009, versus $678 million in 2008.

Sales of Mozobil were $55 million in the first year of sales, higher than the company's forecast of $40 million to $50 million. The drug is used to prepare patients with non-Hodgkin's lymphoma and multiple myeloma for stem-cell transplants.

The company said that excluding the genetic drugs business that was hit by the manufacturing problems, fourth-quarter revenue grew 24 percent. Excluding genetic disease products, revenue in 2009 increased 15 percent.

Sales of osteoarthritis treatment Synvisc in the fourth quarter were $96 million versus $69 million in the fourth quarter of 2008.

In afternoon trading, Genzyme shares were down 80 cents or 1.5 percent to $52.90 on Nasdaq.

(Reporting by Toni Clarke; Editing by Tim Dobbyn and Gerald E. McCormick)