Some Americans may be pulling back on vacations, but cruises remained strong enough to push second-quarter profits at Miami-based Carnival above expectations as the cruise giant continued cost-cutting and began to lift prices from bargain-basement levels.

Shares of Carnival, the world's largest cruise operator, jumped $1.72, or 7.5 percent, to $24.77 on the Big Board. The stock has traded between $14.85 and $42.39 over the past year.

Increasing fuel prices, however, are weighing on Carnival's bottom line -- and the company lowered its full-year forecast to reflect that.

Carnival had slashed its prices deeply to fill ships after a sharp drop in vacation spending in late 2008 and early this year.

Carnival reported that those deep discounts have driven a surge in bookings.

As a result, Chairman and Chief Executive Micky Arison said the company began ''tweaking prices'' higher in March.

The H1N1 flu virus also cost Carnival in the second quarter. The company began redirecting ships away from Mexico in late April as swine flu deaths peaked in that region and fear spread that tourists could pick up the illness. Carnival said it is resuming stops in Mexico this month.

''The key take-away from the quarter is that fundamental business conditions -- the demand for cruise vacations at reasonable prices -- have gotten better,'' Robert LaFleur of Susquehanna Financial Group said in a note to investors.

''While we don't like to see earnings expectations move south, we are encouraged that the only reason they are doing so is for exogenous factors like the swine flu and higher oil prices,'' he said.

Miami-based Carnival recorded a 32 percent drop in profit to $264 million, or 33 cents a share, for the quarter ended May 31. That is down from $390 million, or 49 cents per share, a year ago.

Revenue tumbled 13 percent to $2.95 billion.

Analysts polled by Thomson Reuters expected a profit of 29 cents per share on revenue of $2.99 billion. Arison attributed the company's performance to lower-than-anticipated cruise costs and gains in pricing.

Rising fuel costs, however, partly offset those improvements. Fuel prices, while still lower than last year's historic levels, have risen higher than analysts anticipated, driven in part by improving confidence in the economy.

The company said it started conservation programs that helped reduce fuel consumption. They include route changes and upgrades to ships -- like new technology and silicon-painted hulls -- that improve fuel efficiency.

Chief Financial Officer David Bernstein said Carnival found $33 million in additional savings, bringing the total to $150 million since December. In an interview, spokesman Tim Gallagher noted that Carnival's lines were specifically instructed not to cut guest services or products.

The impact of swine flu lowered earnings by about 3 cents a share in the second quarter. Carnival expects to take an additional 7-cent charge in the third quarter, for a total of 10 cents per share this fiscal year.

For the second half of 2009, Carnival said its booking levels remain slightly behind last year, although volumes have picked up significantly. Ticket prices, while improving, remain at ``substantially lower levels.''

''As we have progressed throughout the year, booking volumes have continued to accelerate with less discounting, as consumers have come to recognize the extraordinary value proposition our cruise vacations represent,'' Arison said.

''Overall by the time the quarter closes, we expect fourth-quarter pricing to be lower year-over-year but improving on the third-quarter's expected price declines,'' said Vice Chairman and Chief Operating Officer Howard Frank during the call.

Carnival lowered its 2009 earnings forecast to a range of $2 to $2.10 per share, from its previous guidance range of $2.10 to $2.30. Analysts predict a 2009 profit of $2.08 per share.

UBS Investment Research analyst Robin Farley noted that Carnival's full-year earnings guidance is actually higher if the impact of fuel costs is excluded.

For the third-quarter, Carnival expects earnings to range from $1.15 to $1.19 per share, compared with analysts' forecast of $1.25 per share.

Miami Herald business writer Martha Brannigan contributed to this report.