Istanbul's bid for the 2020 Olympics has lined up sponsorship deals with seven leading Turkish companies worth more than $20 million.

Bid leader Hasan Arat calls it a "landmark deal" that represents the largest private sector investment in any Turkish sports bid.

He says the sponsors — including Turkish Airlines, mobile phone company Turkcel and digital satellite provider Digiturk — are "the engine" of Turkey's growing economy.

Istanbul, which has failed in four previous Olympic bids, is touting its economic strength and access to new economic markets as a key element of its latest campaign.

The city is competing against Madrid and Tokyo. Spain has been going through a deep financial crisis, while Japan's economy is stagnant.

The IOC will select the host city on Sept. 7 in Buenos Aires.