IBM is considering joining the Citigroup-led consortium bidding for Guangdong Development Bank. The idea, presumably, is to get its paws on more of the Chinese lender’s IT budget but the tactic feels a little uncomfortable. It’s hard to imagine Pfizer taking a stake in HCA, the hospital operator that was bought out this year, or Airbus parent EADS buying Delta Air Lines shares.

Owning stakes in suppliers is common. And vertical integration – for example, taking over intermediaries that distribute your goods – has its adherents. But buying minority positions in customers is rare. Some European and Asian banks own positions in corporations but these are typically defensive cross-shareholdings and not just ways of securing revenue. The flurry of investment banks taking stakes in their hedge fund clients is probably the best contemporary example.