Amgen Inc.'s third-quarter earnings surged 15 percent and exceeded Wall Street expectations Monday even as the world's largest biotechnology company ramped up research spending.

Amgen reported earnings of $1.1 billion, or 94 cents a share, compared with $967 million, or 77 cents a share, in the same period last year.

Excluding special charges, including stock option expenses, the Thousand Oaks-based company said it would have earned $1.22 billion, or $1.04 cents a share.

On that basis, the earnings exceeded Wall Street analysts' expectations by 6 cents, according to a survey by Thomson Financial. The company also increased its earnings-per-share guidance for the year to $3.85 to $3.95, from $3.75 to $3.85.

Amgen's revenue for the quarter rose 15 percent to $3.61 billion from $3.15 billion in the same quarter last year. Sales of the company's flagship drug Aranesp soared 27 percent to $1.07 billion in the quarter. Aranesp treats anemia, including in cancer patients undergoing chemotherapy treatment.

The company released the financial report after the markets closed.

The rosy earnings report came even as concern mounted that it will be difficult for the company to sustain the profit momentum it has enjoyed over the last several years as patents expire over the next decade and amid competitors' legal challenges.

That's why the company has dramatically increased research spending, including a 49 percent jump to $835 million from $559 million in the third quarter. For the year, the company said it expects to increase research and development spending by 30 percent to 40 percent over last year and is beefing up its scientific staff.

"Every company in our business has to continually invest in their own future," Chief Executive Kevin Sharer said in a telephone interview with The Associated Press. "We have some big patents that are going to expire in the U.S. and we want to be ready for that."