NEW YORK (CNN/Money) - Regardless of the pedigree of the air carrier -- whether it's Northwest Airlines or discounter JetBlue Airways -- insiders have been selling millions of dollars' worth of shares, and they don't appear to be in any rush to buy, according to a report published Wednesday.

The Wall Street Journal reports that while company insiders are known for finding value among beaten-down stocks, the fact that they are selling shares seems to offer little evidence that struggling industry is close to a turnaround.

Of the 40 publicly-traded airlines that he tracks, George Muzea, president of Muzea Insider Consulting Services, told the newspaper that he has not seen "any positive insider patterns."

"It seems like there is very little interest in airlines for a long time," the Journal quoted him as saying.

According to Jaseem Hasib, a research analyst at Thomson Financial, Northwest Airlines (Research) has seen more insider trading than any airline in 2005, the report said. Hasib said Northwest insiders have sold $46 million worth of company stock so far this year, compared to about $4 million throughout last year.

The biggest seller at Northwest, the newspaper said, was chairman Gary Wilson, who sold more than 3 million company shares for $18.7 million since the beginning of May, according to Thomson data.

Northwest has struggled with high labor costs, the report said, adding that company executives have openly speculated about the possibility that the carrier may file for bankruptcy.

Meanwhile, at JetBlue Airways (Research), insiders have sold $27 million worth of stock in the past two years, Hasib told the newspaper.

The Journal said JetBlue did not return calls for comment.

Northwest spokesman Bill Mellon told the Journal that Wilson had told shareholders last week at the company's annual meeting that the sales were made to diversify his holdings.