Carnival Corp plans to reduce its massive fleet by 13 ships as it faces unprecedented financial loss brought on by the coronavirus pandemic.

The Arnold Donald-led cruise behemoth announced the drastic move Friday as part of its earnings report for the second quarter, which registered a $4.37bn deficit after seeing a $781m loss in the first quarter.

"We will emerge a leaner, more efficient company to optimise cash generation, pay down debt and position us to return to investment grade credit over time providing strong returns to our shareholders", chief executive Donald said in the report.

As previously reported, the New York and London-listed company plans to sell nine ships in the next 90 days. Two of them include Costa Cruises' 75,200-gt Costa Victoria (built 1996) and P&O Cruises UK's 2,272-berth Oceana (built 2000).

"These agreements are in addition to the sale of four ships, which were announced prior to fiscal 2020," Carnival said.

"In total, the 13 ships expected to leave the fleet represent a nearly 9% reduction in current capacity."

Miami-based Carnival said it expects only five of the nine ships originally scheduled for delivery in fiscal 2020 and fiscal 2021 will be delivered before the end of fiscal year 2021.

The company also foresees later deliveries of ships originally scheduled for fiscal 2022 and 2023.

Donald said Carnival has reduced yearly operating costs by more than $7bn and lowered capital expenditures by more than $5bn over the next 18 months.

The shipowner has also secured more than $10bn more in liquidity and lowered monthly cash burn rate by a third to $650m.

Carnival announced Thursday that it plans to return three AIDA Cruises ships to service in the second half of August and its other 10 ships by 1 September.

The nine-brand owner has had its fleet of 105 ships laid up since mid-March.

Carnival's shares, which trade on the New York Stock Exchange under the ticker symbol CCL, gained 4.8% to $15.27 within the first half hour of trading Friday.