US airlines face billions of dollars in extra costs from soaring fuel prices, with American Airlines, Delta Air Lines and Continental Airlines bearing the brunt of the rise, regulatory filings show.

The incessant climb in fuel prices, which hit a record on Thursday, could threaten to push more major carriers into bankruptcy, adding to the woes of the industry which suffered some USD$10 billion in losses last year.

"This is a serious threat," said airline economist David Swierenga of AeroEcon. "Obviously these kind of expenses just suck cash out of the airlines and of course that's what triggers the bankruptcies, they run out of cash."

He added that he had forecast USD$3.5 billion in industry losses for this year, but that was based on oil at USD$47 to USD$48 a barrel rather than Thursday's closing price of USD$56.40.

"When you add USD$5 a barrel to my crude estimate, the industry is not cash flow positive, so the threat of bankruptcy at those high levels is very real," he said.

Delta, American and Continental are the three major US airlines which have the least hedging to protect them from jet fuel prices which have soared some 70 percent from a year ago.

Fuel prices represent the crisis-hit industry's second-largest cost next to labor and rose to an average of over 20 percent of expenses for the six top airlines in the fourth quarter of 2004 from just 10 percent in the first quarter of 2002, according to a report by brokerage Fulcrum Global Partners.

American is only 15 percent hedged in the first quarter and has no hedges for the rest of the year, compared with 85 percent for low-cost Southwest Airlines.

After getting hit with a USD$1 billion increase in costs last year American could be in for more of the same this year. The 2004 rise in fuel expenses resulted from a 33.7 cent per gallon, or 38 percent, increase in prices to an average USD$1.21, according to its annual report filed with the Securities and Exchange Commission last month.

While well up from 2003, that price was dwarfed by a record USD$1.65 price for spot jet fuel on Thursday.

Delta, which budgeted for this year based on a forecast of about USD$1.22 per gallon, could be hit even harder by the fuel price surge, and with less cash on hand than American, has less margin for error.

In a filing with the SEC, Delta last week said its liquidity needs this year will be "substantially higher" if oil prices do not fall significantly.

Delta warned that every one cent rise in the average jet fuel price per gallon would increase its liquidity needs by about USD$25 million per year. Based on a 40 cent per gallon increase in jet fuel prices Delta may need to find USD$1 billion in additional cash this year.

Other major airlines also stand to be hit by higher energy prices this year.

The following is a summary of what the leading airlines, ranked by size in terms of passenger traffic, have said about the impact of fuel prices:

American: 15 percent hedged in first quarter, not at all in remaining quarters. Negative impact on fuel costs from 33.7 cent a gallon increase in jet fuel in 2004: USD$1 billion.

United Airlines: 11 percent hedged for 2005, at about USD$1.27 per gallon, excluding taxes.

Delta: Not hedged. Every one-cent rise in the average jet fuel price per gallon will increase its liquidity needs by about USD$25 million per year. Business model assumes an average 2005 jet fuel price of about USD$1.22 per gallon.

Northwest Airlines: Hedged about 25 percent for the first quarter, and 6 percent for the full year. Said a one cent change in the cost of each gallon of fuel would impact operating expenses by about USD$1.6 million per month.

Continental: Not hedged. Annual fuel costs seen increasing by USD$40 million for each USD$1 increase in crude oil prices, which have risen by about USD$14 a barrel so far this year. Also contractually liable to pay regional carrier ExpressJet's fuel costs above 71.2 cents a gallon. ExpressJet's fuel and fuel taxes exceeded that cap by USD$126 million in 2004.

Southwest: 85 percent hedged with derivatives that cap prices at USD$26 a barrel, compared with current market prices of over USD$57 a barrel. Expects first quarter fuel costs with hedge to exceed fourth-quarter's 89.1 cents average price per gallon.

US Airways: No fuel hedged as of December 31, 2004, but added it will recognize about USD$2 million a month for previously liquidated hedges, representing about 4 percent of its 2005 jet fuel requirements.

America West: 45 percent hedged for the rest of this year, and 2 percent hedged for 2006. A one cent per gallon increase in jet fuel prices will increase its annual operating expense by USD$5.7 million.

Alaska Air: 50 percent hedged for 2005; A one-cent per gallon increase in jet fuel prices will increase its annual operating expenses by about USD$4.0 million.

JetBlue Airways: 22 percent hedged for 2005.