Carnival Corp & plc, the world's largest cruise shipping group, said cumulative advance bookings for the first three quarters of 2015 are ahead of the prior year at slightly higher prices. "Since September, booking volumes for the first three quarters of 2015 are running ahead of last year’s levels at slightly lower prices driven by transactional currency impacts," the company said in a statement.

Arnold Donald, President and CEO of the group noted: “Based on our current 2015 guidance, we expect to achieve a 50% improvement in earnings compared to financial year) 2013 and are firmly on a path toward delivering double-digit returns on invested capital.”

He continued: “The current base of business for 2015 builds confidence in our expectation of continuing yield growth with acceleration in yield improvement starting in the second quarter.”

Based on current booking trends, the company forecasts full year 2015 net revenue yields, on a constant dollar basis, to be up approximately 2 percent compared to the prior year. First quarter revenue yields (constant dollars) are expected to be slightly higher than the prior year and improve during the remainder of 2015.

The company expects net cruise costs excluding fuel per ALBD, on a constant dollar basis, for full year 2015 to be up approximately 3 percent primarily due to higher dry-dock costs, advertising expenses and product enhancements.

Based on current spot prices for fuel, forecasted fuel costs for the full year 2015 are expected to decrease $475 million compared to 2014, net of fuel derivatives, benefiting the company by $0.61 per share. This is forecasted to be partially offset by unfavorable movements in currency exchange rates worth $0.20 per share (includes both translational and transactional currency exchange impacts). Taking the above factors into consideration, the company forecasts full year 2015 non-GAAP diluted earnings per share to be in the range of $2.30 to $2.60, compared to 2014 non-GAAP diluted earnings of $1.96 per share.

First quarter 2015 outlook

First quarter constant dollar net revenue yields are expected to be flat to up 1.0 percent compared to the prior year. Net cruise costs excluding fuel per ALBD for the first quarter are expected to be 5.5 to 6.5 percent higher on a constant dollar basis compared to the prior year and are higher than full year guidance mostly due to the timing of expenses between quarters.

Current currency exchange rates and fuel prices net of fuel derivatives are expected to benefit first quarter earnings by $130 million compared to the prior year, or $0.16 per share. Based on the above factors, the company expects non-GAAP diluted earnings for the first quarter 2015 to be in the range of $0.07 to $0.11 per share, compared to 2014 non-GAAP earnings of $0.00 per share.