SYDNEY (Bloomberg) - Shares of Qantas Airways surged to their highest level in more than six years in Sydney after Australia's biggest carrier said the global drop in oil prices would help cut its fuel bill this year.

The stock jumped as much as 6.6 per cent to A$3.54, the highest level since September 2008, after Qantas said it would spend about A$550 million (S$581.80 million) less on fuel this year amid a 36 per cent drop in jet fuel prices. Qantas shares have almost tripled in the past year.

Cheaper fuel reduces Qantas's biggest cost item and will leave more money to invest elsewhere in the business. With an average fleet age of 7.2 years, Qantas can afford to wait before buying new planes and instead may save finance costs by buying back plane leases, Chief Financial Officer Tino La Spina told an investor conference Tuesday.

"Getting the fleet within eight to 10 years is fine, it's still very competitive by global standards," he said. "We have cash on our balance sheet at the moment which we would consider excess to requirements."

Qantas's fuel bill could be as low as A$3.92 billion this year and A$3.87 billion in 2016, the company said in a presentation to investors Tuesday. In a worst-case scenario, it would be as high as A$3.95 billion this year and next, the company said.

Singapore jet fuel costs have dropped 36 per cent over the past 12 months, according to data compiled by Bloomberg.

Two out of three hurdles to buying new planes are nearly cleared, La Spina said. The airline's balance sheet should be in optimal shape by June 30 and the international business is on the way to returning its cost of capital, he said.

Qantas has 20 options to buy Boeing Co. 787 aircraft in the 2017-2020 fiscal years, as well as purchase rights for another 30 787 planes extending to 2025, according to a 2013 presentation.