The Saudi Public Investment Fund is now the third largest stakeholder in the company, which has a market cap of about $7 billion.
The investment fund's stake in the company is valued at nearly $370 million.
While the timing of the fund's investment is unclear, the fund did not own any Carnival stock as of its fourth-quarter SEC filing, Barron's reported.
According to the latest filing, the fund's investment in Carnival topped 5% on March 26.
At last check Carnival shares were 21% higher at $10.29.
The cruise line industry broadly has suffered in the wake of outbreaks of the coronavirus on cruise ships and the cancellation of vacation plans worldwide.
In late March, four passengers aboard Carnival's Holland America's Zaandam cruise ship died and two people on board tested positive for coronavirus.
Recently, the company increased its dollar-bond sale to $4 billion from $3 billion and lowered its interest rate for the bonds to about 12% from 12.5%.
Knowledgeable sources told Bloomberg that the increased amount stemmed from the company’s decision to drop a euro-denominated tranche.
The company originally tried to sell notes in both currencies to investors in the U.S. and Europe, Bloomberg reported.
The company late last month suspended its dividend.
Cruise lines were not part of the government's recent $2 trillion fiscal stimulus package in response to the coronavirus.