SEATTLE - Web retailer Amazon.com Inc. said yesterday that its first-quarter profit more than doubled, sending shares up more than 12 percent in after-hours trading. The company also raised its revenue outlook for the year.

Earnings for the first three months of the year rose to $111 million, or 26 cents per share, from $51 million, or 12 cents per share, during the same period last year.

Analysts polled by Thomson Financial had forecast a profit of 15 cents per share.

A $12 million reduction in Amazon's tax bite helped nudge results higher, as did a weak dollar against foreign currencies, which added about $5 million to the bottom line, chief financial officer Tom Szkutak told reporters in a conference call.

Revenue rose 32 percent to $3.02 billion, surpassing Wall Street's expectation of $2.92 billion in sales.

Sales appeared strong across territories and product categories. Amazon's North America sales totaled $1.62 billion, a 30 percent jump. International sales rose 35 percent to $1.39 billion, but that figure did not take into account foreign exchange rates. Adjusted for currency fluctuations, the company said, international sales grew 27 percent.

Jeff Bezos, Amazon.com's chief executive officer, said in a conference call with analysts that Amazon Prime, the company's free-shipping loyalty program, helped North American sales grow faster than international sales. Analysts had been critical of Prime and the extent to which it cut into earnings in the past.

Sales of books, CDs and other media products jumped 26 percent year over year to $1.99 billion. Sales of electronics and other merchandise rose 48 percent to $947 million.

Shares were up as much as $5.46, or 12.2 percent, to $50.21 in after-hours trading after losing 2 cents to close at $44.75 on the Nasdaq.