ImClone Systems ( IMCL) said third-quarter revenue rose 9% from a year ago, but earnings declined as operating costs rose sharply.

Shares of ImClone were down 1.7% to $33.84 Thursday.

The biotech's total operating expenses were up 61% in the quarter, at $80.3 million, with big increases in research and development costs and clinical and regulatory outlays, as well as royalty expenses, according to a company press release.

Revenue was $106.5 million in the third quarter, up from $97.5 million last year. The New York-based company earned $31 million, or 35 cents a share, in the quarter, compared with $39.8 million, or 44 cents a share, last year. Analysts were expecting earnings of 29 cents a share.

ImClone's manufacturing revenue was $10.7 million, about one-third of the amount in the prior year, because of reduced purchase volume and a "significantly lower" Erbitux selling price to Bristol-Myers Squibb ( BMY). ImClone said Bristol's purchases are timed at their discretion and aren't necessarily indicative of past or future sales.

However, the company reported $22 million in revenue from collaborative agreements, more than double the previous quarter.