Cruise operator Carnival said on Friday cruise bookings for the second half of 2022 were ahead of pre-pandemic levels, in a sign the company expects a rebound in business as it restarts voyages globally.

The cruise sector has been among those most affected by the pandemic as many ships docked at ports and anchored offshore for months without passengers, forcing operators to raise billions of dollars in debt to stay afloat.

Some cruise enthusiasts are looking forward to the resumption of more voyages from U.S. ports after the country's health officials gave the green light earlier this year for Carnival and its rivals to restart operations.

Carnival said its voyages for the third quarter were cash flow positive, adding that it expects the trend to continue.

Eight of the company's nine cruise line brands have resumed sailings with passengers onboard, and it expects more than half its total fleet capacity to be open for guests by the end of October.

However, Carnival said its booking volumes for future cruises during the third quarter were not as robust as the second quarter due to the spread of the Delta variant of the coronavirus.

Rival Norwegian Cruise Line Holdings Ltd said it saw a modest decrease in net new booking activity in July following a surge in COVID-19 cases, while Royal Caribbean Group also flagged a modest hit to its bookings from the fast-spreading variant.

Carnival expects its monthly average cash burn rate for the fourth quarter to be higher than the prior quarters, as it prepares its ships for voyages after more than a year.

The company, which reported a third-quarter adjusted loss of US$1.99 billion, said its monthly average cash burn rate was $510 million during the reported quarter.