Ineos owner Sir Jim Ratcliffe and Qatari banker Sheikh Jassim will submit improved bids to buy Manchester United before Wednesday's 21:00 GMT deadline.
Both are understood to have held positive meetings while visiting Old Trafford and United's training ground.
Ineos want to buy the combined Glazer shareholding of around 69%, but the Qataris are targeting 100% of the club.
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BBC Sport has learned that United officials met eight different potential investors over a 10-day period of high-level meetings recently, including Ratcliffe and representatives of Sheikh Jassim.