The A350XWB, which stands for extra-wide body, was presented at the UK's Farnborough Air Show.
Christian Streiff, Airbus's recently appointed chief executive, said: "This is an entirely new design, without compromise and using all the latest technology."
Streiff said the industrial launch of the aeroplane will begin in October and the plane will enter service in the middle of 2012.
The original A350, seen as a rival to Boeing's 787 Dreamliner, had been heavily criticised within the industry.
It had won just 100 orders compared to 360 firm orders for the 787.
However, Boeing acknowledged on Sunday that its 787 Dreamliner is overweight and experiencing delays with some suppliers, although the company stressed that the aircraft remains on budget and on schedule.
Alan Mulally, head of Boeing's commercial airplanes unit, said: "We're a little over where we want to be at this time on weight, but ahead of where we were on previous programmes, so we're really focused on a weight-efficient structure right now.
"Some partners are a little behind on the schedule; but we're working with them on recovery plans to catch up."
Mulally declined to specify where the problems were occurring, but emphasized that the plane remains on course for its first flight in the middle of next year and entry into service the following year.
Mulally said: "The systems are coming together really well, the electrical power looks good and the plane's engines come very very close to their performance goals."
Airbus has been struggling to get back on track since the announcement last month of a further seven-month delay to its A380 super jumbo programme.
The news sent EADS, Airbus's parent company, shares plunging and led to the departure of Gustav Humbert, Airbus chief executive and Noel Forgeard, EADS co-chief executive.
The European aeroplane manufacturer also reported last week that its sales fell by more than half in the first six months of the year to 117 planes, compared to rival Boeing's 480 orders for the same period.
Streiff, said: "Yes, Airbus is in the middle of a serious crisis in our relationship with our customers.
"Yes, this is something we are taking extremely seriously inside Airbus, and yes, we know the competition is taking advantage of this today."