Airbus has fixed electrical problems related to its A380 superjumbo, which have led to major delivery delays for the planemaker.
Singapore Airlines has agreed to buy 19 A380s
The group said the news meant it had "passed a major milestone" for the plane's production.
Deliveries to Singapore Airlines, its launch customer, were now on track to arrive in October, it said.
Problems with the A380 have left Airbus two years behind with deliveries, hitting shares at parent company EADS.
"We have finished the electrical installation," said Airbus spokesman Tore Prang. "We have handed the aircraft to the cabin equipment team to install the first A380."
Last week, Airbus chief executive Louis Gallois said the firm was "determined to complete this first delivery in October 2007, as we announced, and to prepare ourselves for the next deliveries in 2008".
Singapore Airlines has agreed to buy 19 A380s from the firm. Other customers include Thai Airways, Virgin and Australian flag-carrier Qantas.
However, delays to the A380 have already cost the firm more than $6bn (£3.3bn) and Airbus has warned there could be additional charges to come.
Last week, the European group also revealed it had fallen behind US rival Boeing in securing orders for the first time since 2000.
Airbus won 824 new orders last year, down from 1,111 in 2005, and below Boeing's 1,050 haul.
UK job worries
Meanwhile, a report in the Financial Times warned that Airbus's manufacturing base in the UK - which employs 13,000 people - could be under threat.
The FT quoted Airbus executive vice president Tom Williams as saying there was "a risk" the company may award a £100m ($197m) contract to make wings for the A350 to rival plants in Germany or Spain.
The fuel-efficient, medium-sized long haul jet is seen as Airbus's direct challenger to Boeing's 787 "Dreamliner".
The Dreamliner is a long-range, midsized, wide-body, twin-engine passenger airliner capable of carrying 200-350 passengers.