Mattel ( MAT) shares hopscotched higher Thursday after lucrative currency-exchange rates and a big tax benefit worked to thicken the toymaker's fourth-quarter profits.

The El Segundo, Calif., company reported fourth-quarter earnings of $328.5 million, or 89 cents a share, including a 13-cent tax-related gain per share. Even stripping out that one-time benefit, Mattel beat analyst expectations for a 73-cent profit per share, according to Thomson Financial data.

The company also generated quarterly revenue of $2.19 billion, which was up 3.8% from a year earlier and topped the average analyst target by about $60 million.

Essentially all of that growth, however, was due to favorable currency-exchange rates, with half of Mattel's 18% jump in international gross sales deriving from currency effects. In the U.S., gross revenue was down 3% year over year.

The most impressive numbers came from Mattel's self-named brand, which includes such products as Barbie dolls and Hot Wheels toy cars and is currently the biggest component of the company's overall revenue. Worldwide gross sales for the brand leapt 9% year over year to $1.35 billion. The company's Fisher Price offerings also did reasonably well due to a healthy international showing, turning out a 4% total sales rise for the quarter.

Mattel's American Girl doll unit didn't fare so well, though. Sales declined 2% from a year earlier year to $241.6 million.

And the company's total operating income was off 6.8% year over year to $362.1 million, thanks to $42 million in product-recall expenses.

But, said CEO Robert Eckert, "considering the challenges we faced in 2007, the business performed fairly well." For the coming year, he added, Mattel plans to "build on the momentum of our international success and introduce a strong line-up of toys based on entertainment properties."

For the full year, Mattel said it made $1.43 a share, excluding a tax gain, on sales of $5.97 billion. Analysts were looking for $1.40 a share on a top line of $5.92 billion.

The company also announced today that it has authorized buying back another $500 million worth of its shares.

Mattel shares ended Thursday up $2.07, or 11%, to $21.01.