PARIS, France ― Airbus and Boeing have always dominated airplane manufacturing. Now the Commercial Aircraft Corporation of China (Comac) wants a piece of the pie, ending the transatlantic duopoly.

Comac grabbed the world’s attention at the Paris Air Show when it signed an agreement with Ryanair to develop a mid-size airplane that could supplement the low-cost European carrier’s all-Boeing fleet.

“Now we have A, Airbus; and B, Boeing. And then we will have C, Comac,” said a spokesman for the Aviation Industry Corporation of China (AVIC), a parent company of Comac, at the International Paris Air Show on Thursday. “The market is a big market. Everyone can have a piece of the cake.”

That cake is worth $4 trillion, according to Boeing’s forecasts through 2030.

If Ryanair, one of Boeing’s biggest European clients, does buy airplanes from Comac, the Chinese state-run manufacturer would have a foot in the door of one of the most lucrative and enviable markets in the aviation industry, the mid-size single aisle ― a market that Boeing says will account for almost half of all new airplanes in the next 20 years. Airbus estimates that 70 percent of new airplane deliveries in the next 20 years will be in the mid-size single-aisle market.

Airbus and Boeing both acknowledged during the air show that they face new competition.

“We know that new manufacturers will come,” said James Rocca, an Airbus spokesman. “Air traffic is growing around 5 percent a year, so we know that there will be no more a duopoly situation.”

During a press conference in Le Bourget, Paris, Boeing’s CEO of Commercial Airplanes, Jim Albaugh also acknowledged the end of the duopoly, saying Boeing and Airbus will face competition from emerging manufacturers in Canada, Brazil, Russia and China.

In light of changes in the market, smaller manufacturers have been forming deals and alliances to ensure they’ll have a slice of the pie in the future.

Canadian manufacturer Bombardier, for one, has already teamed up with Comac to share resources and expertise.

With Comac’s C919 to be released in 2019, the Chinese single-aisle airplane, “would be a direct competitor to the Airbus A320 and the Boeing 737,” said Mirianella de la Barrera, a Bombardier spokeswoman. “It’s very realistic that they would want to produce their own aircraft and their own industry, and that’s why we are partnering with them on portions of it.”

While Bombardier is already established in the smaller aircraft market, Comac’s announcement of the Ryanair deal makes it a possible competitor as well if it can meet Ryanair’s requests.

“We are pleased that there is now a real alternative to Boeing and Airbus,” said Ryanair CEO Michael O’Leary in a statement in Paris. “We are seriously interested in the development of a 200 seat variant of the C919 aircraft.”

O’Leary explained that Ryanair could operate Boeing and Comac planes, as long as Ryanair could save money in operating costs. Despite the established reputation of Airbus and Boeing, the lure of working with Comac is its cost.

Although there’s no price tag yet for the C919, lower prices would be Comac’s ticket into the European market. The Chinese company also has its eye on the Asia Pacific region, which is the fastest-growing market in the world.

At the moment, Boeing and Airbus are the largest suppliers in Asia ― but without a doubt Comac will be challenging them on its home turf.

Between 2011 and 2030, the Asia-Pacific region will need 11,450 new airplanes valued at about $1.5 trillion, according to Boeing’s market research. In comparison, Boeing forecasts that through 2030, Europe will add just 7,550 new airplanes worth $880 billion.