Carnival Corp is allowing $2bn in convertible notes to be turned into stock in the third quarter without any conditions after committing a chronological error back in April.

On 6 April, Carnival offered $1.95bn in senior notes due in 2023 that could be converted into shares after "any calendar quarter ending May 31, 2020" in which the stock price is at least 30% higher than the conversion price for no less than 20 out of 30 consecutive trading days.

The Arnold Donald-led owner meant to refer to "any fiscal quarter ending May 31, 2020" but instead erroneously indicated a "calendar quarter" that can only end on 30 June.

"As a result, the holders are now entitled to convert all or any portion of their convertible notes at any time during the calendar quarter starting on July 1, 2020 and ending on September 30, 2020", Carnival said in a filing to the US Securities and Exchange Commission on Wednesday.

The conversion rate remains the same at 100 common shares per $1,000 principal amount of convertible notes. Those notes have an annual interest rate of 5.75%.

Carnival declined to comment on the error.

New York-listed Carnival and its peers — Royal Caribbean Cruises and Norwegian Cruise Line Holdings — have had to secure billions of dollars in financing to stay solvent, having idled their ships since mid-March due to the Covid-19 crisis.

These three cruise behemoths, known collectively as "The Big Three", saw very slight gains on Wall Street up to early afternoon on Wednesday.

Carnival, which trades on the New York Stock Exchange under the ticker symbol CCL, gained 0.7% to $16.53.

Royal Caribbean, which can be found on the Nasdaq as RCL, edged up 2.34% to $50.30.

Norwegian, which trades on Nasdaq as NCLH, ticked up 1.8% to $16.73.