NEW YORK — Carnival Corp. and Royal Caribbean Cruises Ltd. are increasingly catering to U.S. tourists who want to dodge the rising euro while visiting Europe. The trend will help reverse two years of share declines for both companies.

To capture the growing appetite for European cruises, Carnival boosted capacity on North American lines going to the continent by 16 percent this year and will raise it by another 20 percent next year to meet increased demand. Its fleets are growing more slowly in the Caribbean after softer demand drove down its stock prices.

The euro's 7.3 percent gain this year is inspiring more people to see Europe by sea. Cruises let travelers pay for their vacations in dollars in advance to avoid currency fluctuations, and are also up to 30 percent cheaper than comparable land vacations, according to Cruise Industry News. To meet demand and entice a new clientele, the Miami-based companies are adding cruises from Finland to Croatia.

"A cruise ship is a mobile asset," said Jason Lisiak, who helps manage more than $15 billion, including 4.3 million Carnival shares, at Manning & Napier Advisors Inc. in St. Petersburg, Fla. "You can allocate capacity according to the highest yielding market, which right now is Europe. As Carnival builds up critical mass in Europe, profitability should rise."

European growth will help push both Carnival shares and Royal Caribbean's 30 percent higher in the next year, according to Raymond James & Associates Inc.

Susquehanna Financial Group estimates Carnival's revenue will climb about 10 percent in each of the next two years, while Royal Caribbean sales will jump 15 percent in 2007, the fastest pace in five years.

Carnival, which operates the Princess and Holland America lines, also is expanding its fleet. Carnival on Oct. 10 ordered a new Queen Elizabeth ship. The luxury liner will begin serving travelers in 2010.

A July 2008 seven-night Royal Caribbean cruise in the western Mediterranean costs $1,721.89 per person for a cabin with an ocean view. In the western Caribbean, a Royal Caribbean cruise at the same time and duration costs $1,300, according to Just Cruises & Vacations.

"With the fixed costs basically equal and ticket prices higher, Europe is generally more profitable than the Caribbean," said Susquehanna's Robert LaFleur. He rates both companies "positive."

Carnival, the world's largest cruise company, and Royal Caribbean began to suffer in 2005 because of higher fuel costs, which ate into profit. Last year, lower-income consumers shunned the trips as fuel costs took more of their dollars. Others were turned off after a spate of disease outbreaks and deaths. Carnival's net income growth slowed to a 1 percent increase in 2006 after rising 22 percent in 2005. Royal Caribbean's net income fell 11 percent in 2006.