Carnival Corp chief executive Arnold Donald painted a picture of a cruise ship company that is determined to continue its return to normalcy even after it reported a worse-than-expected fourth-quarter loss.

Even as stocks in other sectors were sinking in New York amid continued jitters over the Omicron variant of Covid-19, Donald told analysts that the flagship Carnival Cruise Line brand is already operating at 90% capacity, even after the new strain led some would-be passengers to avoid near-term bookings.

The remainder of the fleet is operating at 68%, but customer deposits have built to $1.2bn and the cash flow is helping to fund the costs of restarting ships.

"While the variants and their corresponding effect on consumer confidence have created some near-term booking volatility, our book position has remained resilient, and in the case of Delta variant, already recovered," Donald said.

"Importantly, these variants have not had a significant impact on our ultimate plan to return our full fleet to guest operations in the spring of 2022."

Carnival Corp, which is listed in New York and London, reported a bottom-line net loss of $2.62bn for the final quarter of the fiscal fourth quarter, compared with $2.22bn a year earlier.

But unlike the fourth quarter of its 2020 fiscal year, when it recorded just $34m in revenue, the Miami cruise giant logged nearly $1.29bn in revenue for the three months to 30 November 2021.

A loss of $2.31 per share was below analyst expectations, but Carnival's share rose 3.4% to close Monday at $18.90 on the New York Stock Exchange.

Investor sentiment was buoyed by an outlook that forecast a profitable second half of the fiscal year, even though Carnival expects to remain in the red in the six months beginning on 1 December.

"We believe we have the potential to generate higher Ebitda in 2023 compared to 2019," Donald said.

Even though Carnival acknowledged that Omicron headlines have impacted near-term sailings over the last few weeks, the company's outlook was bolstered by strong demand and pricing trends as the company locks in early bookings into 2023.

"What a difference a year makes," Donald said. "We are clearly on our way back to full cruise operations, with 50 ships now serving guests as we end the fiscal year."

Some 65,000 crew members have returned to their ships, and 1.2m guests have sailed on vessels since the fleet restart began.

Donald said the company has intentionally constrained capacity in the first half of the fiscal year that started this month, to keep a focus on pricing.

Carnival's quarterly results added to a $9.5bn loss for the 2021 fiscal year, a slimmer deficit than the $10.2bn in red ink a year earlier.