Finmeccanica chief executive Alessandro Pansa has delivered a withering broadside to Russia's Sukhoi - its partner in Superjet International, which markets the regional jet to Western customers - describing their relationship as "significantly unsatisfactory".
Pansa's comments, made during a media briefing at the Paris air show, came a little under 24 hours before the SSJ100's first Western customer, Mexican carrier Interjet, is due to receive its initial aircraft.
"It has been a very difficult partnership, it's been very expensive for us and is significantly unsatisfactory [from] many viewpoints," says Pansa. "We signed an agreement [on the SSJ] which has been implemented in an unsatisfactory way for quite a long period of time."
The choice for Finmeccanica, which partners with Sukhoi via its Alenia Aermacchi subsidiary, is either to exit the relationship or reshape how the two companies work together. "We are pushing for the second option," he says.
And, adds Pansa, if the partnership was "significantly reviewed and restructured", it could provide the Italian company an opportunity in the market for regional jets with fewer than 100 seats.
But Giuseppe Giordo, chief executive at Alenia, says the delivery to Interjet will mean that a number of targets for the programme will have been "reached and achieved".
He describes the alliance as "very strategic" for both parties. "I believe we are now getting the first results [from that]." he says.
Giordo calls for greater integration between the two companies to manage the programme in the future and stresses it is "still important" for the pair.
Although Giordo admits that Alenia has been losing money on the SSJ100 so far, he thinks it is no different to previous aircraft development programmes.
"If you look at the cash-flow curve, first you go down and then go on to break even." He points to the ATR turboprop - manufactured via an Alenia-EADS partnership - which only achieved break-even when the 150th aircraft was delivered. For the Superjet "break-even should be around 120-150 deliveries", says Giordo,
Sukhoi was not immediately available to comment.