NEW YORK (Reuters) - Carnival Corp & Plc posted a quarterly profit that beat analysts' estimates helped by better-than-anticipated pricing and lower net cruise costs, driving shares up nearly nine percent in midday trading.

The world's largest cruise operator reported net income of $264 million, or 33 cents a share, in the second quarter compared with $390 million, or 49 cents a share, a year ago. The earnings beat consensus estimates of 28 cents per share, according to Reuters Estimates. They were also better than the Miami-based company previously forecast in April when it reassessed its estimates to reflect the H1N1 flu outbreak. Total revenue for the quarter was $2.9 billion, down about 15 percent from a year ago.

"What is very encouraging is that, since the end of March, everything is trending up right through the travel advisory, both volumes and yields," Carnival chief executive Micky Arison said during a conference call with analysts.

"So we're encouraged by that. Whether that will be sustainable, time will tell."

Including fuel, net cruise costs dropped 9.6 percent on a constant dollar basis. Carnival said yesterday that booking volumes for the second half of 2009 so far were 26 percent higher than in 2008. Costs and expenses were down nearly 13 percent compared with a year earlier. Carnival lowered its third-quarter and full-year outlook, largely due to higher fuel costs and currency exchange rates. Carnival now see third-quarter earnings within the $1.15 and $1.19 range. The company also lowered its 2009 earnings outlook to a range between $2 and $2.10. Analysts expect Carnival to finish the year with $2.08 in earnings, Reuters Estimates shows.