Losses at Thailand's flag carrier Thai Airways International spiralled to 9.23 billion baht (274.3 million dollars) in the second quarter, the airline said in a statement Thursday.
"The main reason was the sharp rise in the price of jet fuel by 73 percent, causing the company's fuel costs to rise sharply," Ngamnit Sombutpibool, the airline's vice president of accounting, said in the statement.
The airline plans to lay off 400 staff, mainly through an early retirement programme, which would cost about 700 million baht and be paid for by reduced investment.
Thai Airways International's plan to end its non-stop flight between Bangkok and Auckland in October has created an uproar in New Zealand's tourism industry
New Zealand reacted strongly with its Minister of Tourism Damien O'Connor issuing an official statement saying that the suspension would be a big blow to his country's tourism industry.
However, a THAI spokeswoman insisted the plan to end the non-stop Bangkok-Auckland flight was tentative.
"We are reviewing the performance of all routes, non-stop Bangkok-Auckland included, and have yet to make a conclusion," she said.
Shares of Thai Airways International PCL sank 4.6 percent on Thursday after the country's national carrier posted its biggest quarterly loss in 11 years.