Mexico is reviewing design plans for a new 120 billion peso ($9.23 billion) Mexico City airport which will eventually have six runways and should begin operating by 2018, according to sources familiar with the plan.

The new hub is due to replace the overstretched Benito Juarez International Airport and would be built on the area of the Texcoco lake bed nearby, said two people with knowledge of the project, few details about which have been revealed.

The current airport, Latin America’s second busiest after Sao Paulo’s Guarulhos, exceeded maximum operating capacity more than 50 times in 2012, and a new one has been discussed for years.

“This situation implies a loss of competitiveness to foreign airports and on some occasions, security risks,” President Enrique Pena Nieto’s transport development plan says.

A handful of consortiums have submitted bids to design the airport, including one fronted by British architect Norman Foster and Fernando Romero, son-in-law of Mexican tycoon Carlos Slim, the billionaire’s spokesman Arturo Elias said.

A winner should be announced in July, the sources said. “The architectural firm for the project will provide design services and detailed engineering, as well as support during the construction phase,” said a government document seen by Reuters.

Spokesmen for Mexico’s Transport Ministry and airport operator Airports and Auxiliary Services declined to comment.

Still, Carlos Bussey, the ministry’s director for highway projects, said at a conference last week that authorities have been studying solutions to the airport saturation problem.

“In the coming months, studies by international teams that have been working on alternatives will be made public,” he said.

The airport master plan was developed by engineering consultancy group Arup and envisions four runways and one terminal serving 30 million passengers by 2018, the year in which it would replace the current airport, the sources said.

By 2060, the plan says, the site would include six runways and two terminals to handle 60 million passengers, they added. A train would move travelers between terminals, documents showed.

A spokeswoman for Arup confirmed that the company is overseeing a master plan for the airport, noting that Mexican and international architects are competing to design the terminal building.

Participating firms were asked to sign 12-year non-disclosure agreements, government documents showed.

Competitors were invited to present their credentials in November. In January, the consortiums were asked to submit market studies detailing design plans and costs by April.

The bid follows an attempt to build a new airport near the chosen site under ex-President Vicente Fox which met with violent protests, leading to the plan’s cancellation in 2002.

Armed with machetes and Molotov cocktails, the demonstrators took 19 officials hostage after the government initially offered locals around $0.70 per square yard for land for the airport.

This time around the government has said it already owns land around the current airport, but not much else.

Transport Minister Gerardo Ruiz Esparza has said work could begin this year on the project, which the government has said would be financed with private and public money.

Cranes and trucks can already be seen around the site.

The existing hub handled a record 31.5 million passengers in 2013, according to Airports Council International.

($1 = 13.0068 Mexican Pesos)

(Additional reporting by Cyntia Barrera, Tomas Sarmiento, Lizbeth Diaz, Elinor Comlay, Dave Graham, and Gabriel Stargardter; Editing by Jonathan Oatis)

Photo Credit: An existing waiting room at Mexico City's airport. Heather / Flickr