"This year, one of the top issues is going to be the environment," said Anthony Concil, spokesman for the International Air Transport Association.

IATA represents some 250 airlines, or 94 percent of scheduled international air traffic.

"It's at the top of several policymakers' agendas -- the United Nations is going to discuss it in September within their civil aviation organization ICAO," said Concil, adding that airlines have made some progress in efforts to reduce greenhouse-gas emissions.

More than 150 airline chief executives as well as top management from airports, civil aviation authorities, manufacturers and non-governmental organizations are expected to attend the three-day event in Vancouver, the Geneva-based organization said.

On Monday IATA plans to unveil its latest financial forecasts for the sector, which are expected to confirm a healthy recovery from the nosedive that followed the September 2001 terror attacks in the United States and soaring fuel prices.

IATA already had sharply revised upward its 2007 estimate in April, as a relatively robust global economy spurred tourism and airline transport.

After more than 40 billion dollars in losses in the past six years, the global airline industry will generate 3.8 billion dollars in profit this year, up from a previous estimate of 2.5 billion, IATA predicted in April.

"We've made some progress but we're still in the single-digit billion profits and we should reach the double-digit," Concil said.

The latest figures reported by IATA back the current firmness of the market: during the first four months of this year, air passenger traffic increased by 6.7 percent from the same period a year ago, dwarfing a 2.6 percent rise recorded in cargo traffic.

"Demand is better than expected," said IATA, led by the hot markets of the Middle East, up 17.6 percent, and Africa (10.1 percent).

Industry leaders are also expected to focus on security issues and how to harmonize national security standards.

"We've had a good start with the liquids and gels control procedure, but the overall procedures are not harmonized enough," Concil said.

Liberalization of the aviation sector also was on the agenda, in the context of the upcoming first phase of an open-skies agreement between the United States and the European Union that begins in October.

In addition, China and the United States recently pledged to develop air traffic between the two heavyweight powers.

Two other subjects were also expected to fuel debate: the undertaking by 95 percent of the member airlines of a safety audit certified by IATA and dubbed IOSA, and a December 31 deadline for all member airlines to use only electronic ticketing.

By the end of this year, paper tickets are supposed to have vanished, replaced by e-tickets. As part of the switchover, 70 percent of airports should be outfitted with multi-carrier electronic kiosks and 80 percent of airlines should have adopted a standard bar code.