The world's largest biotechnology company said net profit fell to $1.07 billion (636 million pounds), or $1.40 per share, compared with a profit of $1.43 billion, or $1.88 per share, a year ago, when earnings were helped by a tax gain.

Excluding special items, Amgen had adjusted earnings of $1.87 per share. Analysts on average expected $1.94 per share, according to Thomson Reuters I/B/E/S.

The company left its full year forecast unchanged, which is likely to disappoint investors who have become accustomed to Amgen raising its outlook as the year progresses.

Amgen still expects 2014 adjusted earnings of $7.90 to $8.20 per share and revenue $19.2 billion to $19.6 billion. Wall Street on average is looking for earnings of $8.16 per share and sales of $19.61 billion.

(Reporting by Bill Berkrot; Editing by Bernard Orr)