SAN FRANCISCO - Boeing on Sunday unveiled 747-8 Intercontinental, a new wide-body jet airliner touted by the US aviation giant as the only airplane in the 400-500 seat market.

About 10,000 guests, including customers, Boeing employees, government officials, partners and suppliers, gathered in Boeing's factory in Everett in the US state of Washington Sunday morning to witness the premiere of the 747-8 Intercontinental, according to a Boeing press release.

The new plane will offer airlines the lowest operating costs and best economics of any large passenger airplane while providing enhanced environmental performance, Boeing noted.

"The new 747-8 Intercontinental features the latest in innovative technologies -- applying many of the breakthroughs also found on the 787 Dreamliner," Jim Albaugh, chief executive officer of Boeing Commercial Airplanes, said in a statement.

First delivery of the 747-8 Intercontinental is now scheduled for the fourth quarter of this year, Boeing said.