The firm, which is struggling to bounce back from the Costa Concordia disaster that left 32 dead last year, said bookings are higher but cut-price tickets have eaten into its margins.
The firm said in an update after the US markets closed on Monday that it now expects a two to three per cent fall in net revenue yields this year, after predicting flat yields previously.
Carnival cut its 2013 earnings guidance range from $1.80 to $2.10 per share down to $1.45 to $1.65.
Carnival has also been under pressure following an engine fire that left thousands of passengers on its Carnival Triumph ship stranded in the Gulf of Mexico for five days in February.
The Anglo-American company’s gloomy update contrasts with the fortunes of rival cruise group Royal Caribbean, which last month boasted of strong profit growth in the first quarter of the year.
UBS analysts cut their rating on Carnival’s stock from buy to neutral yesterday.
The bank published a note saying: “We suggest remaining on sidelines in near term until tide turns on Carnival’s perception problem. But this well-regarded management team will right the ship, in our view.”
London-listed shares of Carnival closed 5.9 per cent lower at 2,267p.