The Glazer family, United's American owners, said in November they had begun looking at options for the record 20-time English champions, including new investment or a potential sale, 17 years after they bought the Old Trafford club.
INEOS formally entered the bidding process to buy United earlier this year.
"We would see our role as the long-term custodians of Manchester United on behalf of the fans and the wider community.
"We are ambitious and highly competitive and would want to invest in Manchester United to make them the number one club in the world once again," INEOS said.
Ratcliffe has previously openly expressed his interest in buying the Old Trafford club.
The initial deadline for bids expired on Friday. Sheikh Jassim Bin Hamad Al Thani, a son of Qatar’s former prime minister, also confirmed a bid on Friday.
