Northwest Airlines' shares have lost close to one third of their value in recent weeks on growing concern that the carrier is heading for a bankruptcy filing, analysts said on Wednesday.

The stock has declined some 28 percent since a recent peak on June 7, compared with an 8 percent decline in the Amex Airline index during the same period.

Delta Air Lines, another likely candidate for a bankruptcy filing according to industry watchers, has seen its shares tumble some 16 percent since June 7.

"Certainly bankruptcy is a concern for Northwest," said Chris Lozier, Morningstar equities analyst. "We think that along with Delta, those two mostly likely are the next bankruptcies."

Spokesmen from Northwest and Delta declined to comment on talk of possible bankruptcy filings.

But JP Morgan analyst Jamie Baker echoed the bankruptcy prediction on Wednesday, saying in testimony before a US Senate subcommittee that he thought the two airlines had about a 60 percent chance of filing for bankruptcy over the next year.

Northwest shares have slumped nearly 60 percent this year, while Delta's have lost about 55 percent.

Contentious talks between Northwest and its labor unions on concessions has fueled speculation that the airline is poised to enter Chapter 11. The airline says it needs USD$1.1 billion in average annual labor savings.

Last week, the mechanics union at Northwest asked for an end to federally mediated contract talks. The request followed a similar failed attempt by the airline to end negotiations.

Meanwhile, members of the Aircraft Mechanics Fraternal Association are in the middle of a vote to authorize union leaders to call a strike, citing what they call a lack of flexibility on the part of the carrier in contract talks.

In Congressional testimony, Northwest Chief Executive Doug Steenland, along with Delta CEO Gerald Grinstein, recently warned that the airlines' pension woes could trigger bankruptcy filings.

Further pressure on Northwest shares has come from news that senior airline executives, including company Chairman Gary Wilson, have been dumping their stock in the carrier.

"It just creates more uncertainty in some customers' minds," said airline consultant Robert Mann. He added, however, that Delta's financial strain is greater than Northwest's.

"Certainly from a cash holding position they aren't anywhere close to where Delta is," Mann said.

Other analysts are also a bit more optimistic about Northwest.

Atlanta-based Delta, which narrowly avoided filing for Chapter 11 last year, took a step back from the brink of bankruptcy in early June when General Electric's finance arm agreed to relax certain requirements under a credit agreement.