Carnival Corp has posted its sixth straight quarterly loss as a result of Covid-19, but hopes for better days ahead as it gets its fleet up and running again.

The New York-listed owner of 91 cruiseships reported a net loss on Thursday of $2.1bn for the second quarter, versus a year-ago deficit of $4.37bn.

On an adjusted basis, the loss came in at $2.04bn compared with $2.38bn last year, when the second-quarter figure excluded $1.95bn lost as a result of impairments on sold ships.

The Miami-based cruise behemoth did not report second-quarter revenue, but said customer deposits for future cruises totalled $2.5bn as of 31 May, versus $2.2bn at 28 February.

"Despite our minimal advertising spend, we continue to experience an acceleration in booking trends globally, including capturing significant latent demand for our new sailings this summer," chief executive Arnold Donald said.

"This strong demand affirms confidence in our future. In addition, customer deposits grew this past quarter, a significant milestone on our path to resumption."

Carnival's monthly cash burn rate stands at $500m, while cash on hand is at $9.3bn.

"We believe we have sufficient liquidity to get us back to full operations and continue to be focused on pursuing refinancing opportunities to reduce interest rates and extend maturities," chief financial officer David Bernstein said.

"To date, through our refinancing efforts, we have reduced our future annual interest expense by over $120m per year and expect to increase our near-term liquidity by $1bn."

Adjusted loss for the first six months of fiscal 2021 hit $3.99bn, versus a $2.23bn deficit for the same period last year.

On Wednesday, Carnival announced plans to resume cruises on 42 ships by the end of the year in the US, Caribbean and Europe on eight of its nine brands.

It said in mid-May that it planned to have 14 other vessels across seven brands offering European itineraries by July.

If all goes as planned, Carnival will have 56 ships sailing revenue voyages by year's end across brands AIDA Cruises, Carnival Cruise Line, Costa Cruises, Cunard, Holland America Line, Princess Cruises, P&O Cruises (UK) and Seabourn.

The company said it is not yet able to sail its P&O Australia brand "based on current border and travel restrictions in place in the country".

It hopes to have all ships offering cruises by the spring.