STORY: Its merger with JetBlue was blocked by a judge - now Spirit Airlines has some rethinking to do, and quickly. Shares in the airline plunged as much as 34% on Thursday (January 18) as investors feared it was headed for restructuring. But the stock then pared losses, after Reuters reported that Spirit was ruling out any such move. The company later confirmed that it was planning to shore up its balance sheet by refinancing its debts. A spokesperson said it was not pursing any kind of statutory restructuring, contrary to earlier reports by the Wall Street Journal. Since a court blocked its merger plan on Tuesday, a number of analysts have downgraded Spirit stock. Some have said the airline could plan a bankruptcy filing in order to restructure. Ratings agencies Fitch and S&P have also warned of mounting concerns regarding debts. The negative noises have all weighed on Spirit stock, which is down by more than half since Tuesday (January 16). Its earnings have been sapped in recent months as it was forced to do deep discounts to fill its planes. The airline has also been hit hard by problems with engines on some of its jets. A judge blocked its merger with JetBlue over concern the deal would be bad for consumers, and analysts see little prospect that the ruling can be overturned on appeal.