I can't see Richard Branson (or any other sensible investor) considering the acquisition of "loss-making" BMI without understanding in very great detail where the problems lie and having a good plan for how they are going to deal with them.
But anyway, in the days of Franchise Carriers it is really no longer necessary to actually buy the company to get the integration benefits (BA please note). BMI could be run as a Virgin franchise giving all the connection benefits, integrated brand, shared Heathrow base costs, etc without the investment and with the ability to walk away if it really starts to go pear-shaped. The only benefit from purchase would be acquiring the Heathrow slots and transferring them to Virgin longhaul.
Is this really what is wanted ? BA have for years said short haul is loss making and long haul is profitable. It always seems that this is creative accounting, in the way the revenue from all the connecting passengers is divided up between their flights. If it was really true BA would have been out of short haul years ago and sold off those Heathrow slots it didn't want for a fortune. Yet BA short haul outnumber long haul at Heathrow about 2 to 1. And I seem to pay the same to go to Dusseldorf as to Miami. It would be quite possible to devise another accounting model which showed the short haul to be profitable and the long haul loss making.
So knowing this about creative accountancy and the presentation of figures, I wonder how much of the BMI loss is just that - presentation. I know the fares I pay for frequent travel out of Heathrow on BMI and the typical load factors I encounter. We are told that slots at Heathrow are like gold dust because operating from there is so profitable - and BMI are the second largest carrier there. BMI have stocked up with new A319-320-321 and Embraers in recent years. Apart from the Fokkers and the Baby fleet the whole lot is less than 6 years old. Now the financiers of that know a thing or two about whether they are likely to get their money back.