Hyundai have become the latest top-tier sponsor to demand a "thorough investigation" into corruption allegations over Qatar's 2022 World Cup bid.
Sony, adidas and Visa all spoke out over the weekend to say they expect the allegations - made by the Sunday Times - to be probed.
Hyundai are one of the six 'partner' sponsors of FIFA along with adidas, Coca-Cola, Emirates, Visa and Sony.
The Sunday Times alleges that Mohamed bin Hammam paid over $5m to win support in the Qatar bidding process.
The Qataris deny the allegations, insisting Bin Hammam was not part of the bidding team.
A Hyundai spokesman said: "We are confident that FIFA is taking these allegations seriously and that the Investigatory Chamber of the FIFA Ethics Committee will conduct a thorough investigation.
"Hyundai Motor supports football as a sport that brings people together all over the world and firmly believes the World Cup is the ideal platform to fulfill this objective."
Electronics giant Sony said: "We expect these allegations to be investigated appropriately, and we continue to expect FIFA to adhere to its principles of integrity, ethics and fair play across all aspects of its operations."
adidas said it was confident that the matter was being dealt with "as a priority," while Visa said it would continue to monitor the internal FIFA investigation.
FIFA investigator Michael Garcia, a former US federal prosecutor, is to finish his inquiry into the 2018 and 2022 World Cup votes on Tuesday.