LONDON (AP) — Istanbul signed up seven leading Turkish companies on Monday to sponsor the city's bid for the 2020 Olympics, a $20 million deal that organizers said underlines the country's economic muscle at a time of global financial uncertainty.

The Istanbul committee described the "landmark deal" as the biggest private sector investment in any Turkish sports bid, declaring that it shows Turkey's potential as a lucrative new market and source of major sponsorship revenue for the Olympic movement.

"It reflects the remarkable economic growth that Turkey has experienced in the last five years," Istanbul bid leader Hasan Arat said in a telephone interview. "The Olympic movement should take great confidence that Turkey will be able to deliver a significant amount of high quality ... sponsors should we win the right to host the games."

Istanbul, bidding for a fifth time after four previous failed attempts, is touting its economic strength as a key element of its latest Olympic campaign, seeking to set itself apart from rivals Madrid and Tokyo.

Spain has been going through a deep financial crisis, while Japan is trying to stimulate a stagnant economy. Istanbul claims Turkey will have the fastest growing economy in the Organization for Economic Cooperation and Development between 2011 and 2017.

In its bid documents, Istanbul projects generating $675 million in revenues from domestic sponsorships if it hosts the 2020 Games. Istanbul's projected infrastructure budget for the Olympics is $19.2 billion — much higher than Tokyo ($4.9 billion) and Madrid ($1.9 billion).

"Our economy is giving us a lot of strength," Arat said. "If you don't have a strong economy, you cannot handle this operation, it's impossible."

With the three cities submitting their bid files to the International Olympic Committee earlier this month, the global promotion campaign is now in full swing. The IOC will select the host city on Sept. 7 in Buenos Aires.

The seven companies backing the Istanbul bid are Turkish Airlines, mobile phone company Turkcel, digital satellite provider Digiturk, Dogus Group, Koc Holding, Sabanci Holding and Ulker.

"These companies are the engine of the Turkish economy," Arat said. "It is an excellent example of public-private partnership."

The overall budget for Istanbul's bid campaign is $55 million, and more private companies are expected to come forward, Arat said.

Istanbul is seeking to bring the Olympics to a new part of the world in a city that straddles Europe and Asia.

"This is the fifth bid," Arat said. "We learned a lot, we listened a lot. This is totally different, a new bid from a new Turkey."