By David Schepp BBC News Online North America business reporter

A new study has found that far fewer Americans have postponed or cancelled jet travel because of last year's terror attacks in the US.

The results further bolster analyst conclusions that the airline industry was in dire straits long before 11 September.

Americans are keeping tourism dollars at home

A flagging US economy, overcapacity and fare wars have hit airlines' bottom lines, resulting recently in the Chapter 11 bankruptcy filing of US Airways.

Since last year's attacks on the World Trade Center towers in New York and the Pentagon in Washington, just 15% of all travellers altered domestic trips over concerns for their safety, the report said.

Far fewer - just 9% of 700 people polled - cancelled or postponed overseas flights.

More troubling for the airline industry, however, is that nearly a third of travellers destined for foreign destinations are less inclined to embark on flights overseas.

The poll, released on Thursday by the Travel Business Roundtable, was conducted in mid-August and consisted of equal numbers of leisure and business travellers.

Flying safe

Surprisingly, the reluctance on the part of some flyers to take foreign flights has less to do with concerns over personal safety as it does with the desire to keep tourism dollars within the US.

Delta's CEO has kept the firm flush in cash

Respondents also said increased security, long lines and hassles, such as removing shoes, and body searches, have caused some to chose other modes of travel.

While 94% found heightened security screening acceptable, more than two-thirds believe the process is administered inconsistently from airport to airport.

Still, of those surveyed, most believed they are safer than before 11 September.

But 30% thought current security measures were insufficient to prevent another terrorist attack.

Wheeling and dealing

The report also noted that Americans are steadily looking to their cars as alternative means of transportation for short trips, further eating into the profits of beleaguered airlines.

The survey debuts just as US airlines are scrambling to find a way back to profitability.

Aside from US Airways recent descent into Chapter 11 bankruptcy, the US' number two airline, United, said earlier this month it too may have to file bankruptcy in order to keep flying.

On Friday, three of the largest carriers, Delta Air Lines, Continental Airlines and Northwest Airlines, announced a code-sharing agreement.

The pact allows each airline to book seats on certain domestic and international flights of another carrier.

In addition, the three major airlines will link their frequent-flyer programmes and share airport lounges.

Delta, the nation's third-largest carrier, is among the US' most financially stable airlines.

The Atlanta-based carrier is sitting on nearly $3bn (�2bn) in cash but is still seeking to slash costs and return to profitability.