The Manchester United Supporters Trust believe fans will be left with "mixed feelings" after Jim Ratcliffe's investment left the Glazers still in overall charge at Old Trafford.
Ratcliffe, Chairman of INEOS, is to acquire up to a 25% shareholding in the Old Trafford club.
Reacting to the news, MUST said that the ownership situation must be explained fully to fans.
"During 18 years of debt, decay and mismanagement, Manchester United fans have loudly and consistently called for change at our club. When the so-called Strategic Review was announced nearly a year ago, it finally appeared that the sale of the club was on the horizon, potentially bringing the new investment and new direction MUFC so clearly needs," a statement from MUST read.
"Against that backdrop, fans have very mixed feelings today. We welcome the investment from a boyhood red, Sir Jim Ratcliffe and his INEOS company, but many will wish his ownership stake was greater than the initially rumoured 25 per cent.
"We note the statements that he and his team will control sporting activities, yet puzzle how any organisation can put its very core business in the hands of a minority shareholder, and how that meaningfully works in practice.
"It is now incumbent on the club’s owners and management to properly explain how this new structure will work, where the new investment will be directed and how it will benefit the team on the field. As the supporters trust, we expect to have discussions with the club management and the INEOS team in the near future to understand their plans, and to put to them the very many questions fans have today.
"Today might – just might – be a step forward for Manchester United after some very difficult years. But with the Glazers still in charge, people should understand that United fans will remain sceptical and wait for the proof in the pudding."
