The FIA has confirmed "more than one" company has bid for the 2020-23 Formula 1 tyre contract, with sources suggesting Hankook is the main rival to current supplier Pirelli.
Michelin confirmed on Friday that it would not bid for the contract after previously signalling an interest in returning to F1 after its exit in 2006.
For rivals such as Hankook, the main challenge is that the tender for 2020 is conducted with different tyre sizes, as F1 will switch to 18 inches and no tyre blankets for '21.
Hankook is already well known to the FIA as the tyre supplier for the European Formula 3 Championship, while it has been the sole supplier for the DTM since 2011.
"The ending of the tender was last night at midnight," said FIA president Jean Todt. "I don't have the result yet of who has been applying for the tender.
"I know it's more than one. I knew since a while now, before August, that Michelin was not going to compete for the tender."
The FIA will spend the next two weeks analysing the bids and those considered capable of fulfilling the tender will then be passed on to the F1 organisation, who will make a call on the commercial aspects.
"I can confirm that we are interested in the tender," said Pirelli F1 boss Mario Isola. "I can confirm that we sent the application. The technical document from the FIA is quite detailed, and we are happy to discuss it.
"As I've said in the past our approach is to work together to find the best solution. They will probably have quite a lot of technical working groups because it's not just 18-inch tyres that are part of the package, but also the characteristics of the tyres need to be discussed."
Isola admitted that it was a much more complex process this time around because of the extra requirements in the tender, especially in terms of the degradation requirements.
"It took some time to analyse it [and] prepare the document because you have to put a lot of technical details [in].
"Before September 14 the FIA will reply to each bidder, saying if the bidder is eligible for supplying the tyres or not.
"I hope we are eligible after eight years in F1! Obviously this is a normal procedure.
"After that, it is called phase two, and phase two is the commercial agreement with F1.
"It is complicated, because there are a lot of details, not only in terms of degradation. Degradation is the most visible, but there is a lot about working range [of the tyres], there is a lot about peak performance, stiffness characteristics of the tyres.
"There are a lot of details in the target letter, and we are happy to have the target letter, because at least it's a shared document with everybody where we agree and we follow what is written.
"On the technical side yes it's challenging, 18 inches, no blankets, there is a lot."