UPDATE 1-Alnylam posts wider-than-expected Q4 loss

* Q4 loss/shr 23 cents vs est loss/shr 15 cents

* Q4 revenue $24.4 mln vs est $26.1 mln

Feb 24 (Reuters) - Alnylam Pharmaceuticals Inc (ALNY.O) reported a wider-than-expected quarterly loss on higher operating expenses, and said it ended the year with $513 million in cash.

The company, which focuses on RNAi or gene silencing as a way to fight disease, expects a net operating loss of about $35 million to $45 million in 2009, excluding special items.

RNA interference, or RNAi, is one of the hottest areas of biotechnology research that attracts investment from a range of major drugmakers.

Alnylam also expects to end 2009 with more than $435 million in cash, cash equivalents and marketable securities.

Shares of the company closed at $20.79 Tuesday on Nasdaq.

For the alerts, please click [ID:nWNAB6325] (Reporting by Esha Dey in Bangalore; Editing by Jarshad Kakkrakandy)