Apr.29 (GMM) The signatures will be added to a new long-term contract for Interlagos' Formula One race next month, Sao Paulo mayor Fernando Haddad claims.
Mayor Haddad responded by insisting he had sent a letter to the FIA, assuring that the upgrade will be done.
And Ecclestone said in Bahrain: "I've just received a letter from the mayor and he's guaranteed to revamp the whole facilities there, which will be good, we've been waiting long enough."
Haddad is now quoted by Brazil's Lance: "In May, we will conclude the contract so that Formula One stays here until 2020.
"We just need to go through the paperwork. It was a long discussion, it's just that we could not commit to something that we could not do.
"It is a big job. We require a long-term contract, because we will invest more than $100 million and we could not do that without the security (of a contract).
"It is reasonable that the agreement goes to 2020," he added.