Swiss drug maker Roche Holding AG posted a 14 percent drop Thursday in year-on-year sales for the first nine months of 2011, blaming Switzerland's strong currency for weakening its results.

The Basel-based manufacturer of cancer-fighting drugs said sales for the three quarters _ including those of its anti-influenza drug Tamiflu, which has been a big earner for the company in the past _ fell to 24.4 billion Swiss francs compared with nearly $28.4 billion for the same time period last year.

But it noted that in terms of U.S. dollars its sales rose 4 percent. Excluding Tamiflu, Roche said in a statement posted on its website, the drop was 13 percent in francs _ but an increase of 6 percent measured in dollars.

In the third quarter alone, Roche said sales dropped 14.5 percent compared with the same period a year ago, from 11.49 billion francs down to 9.82 billion francs. Those July-September figures include sales of Tamiflu.

But the biggest producer of anti-cancer medications such as Herceptin and MabThera, known in the U.S. and Canada as Rituxan, said those drugs had become its "major drivers" along with eye medication Lucentis, rheumatoid arthritis medicine Actemra and its professional diagnostics business. It also cited the successful U.S. launch of targeted skin cancer medication Zelboraf.

The company saw sales of its best-selling drug Avastin decline, however, after a U.S. Food and Drug Administration panel ruled breast cancer patients should no longer use it. But it noted that an EU expert panel has recommended approval of Avastin as front-line therapy for ovarian cancer.

Roche CEO Severin Schwan called the company's third-quarter performance "solid" and in line with its expectations for sales excluding Tamiflu to grow at low single-digit rates, based on constant exchange rates.

"We're on track to achieve our targets for 2011," he said

The company also has been pushing through a cost-savings program to raise its full-year earnings target in local currencies. Roche previously announced it would cut almost 5,000 jobs by the end of 2012.

The Swiss franc has hurt exporters this year by a run-up in its value that has made goods appear more expensive to foreign buyers.

But the Swiss central bank has moved to limit the franc's strength to protect Swiss companies _ and the nation's relatively strong, stable economy _ by setting a ceiling on the value of the currency against euros.

Roche shares closed Wednesday at 147.50 francs ($164.36) on the Zurich exchange.