It is awkward when your new best friend decides to play with someone else. Barclays - and its 60 per cent-owned South African subsidiary Absa - might therefore feel a little queasy at news that China Development Bank has signed a potentially far-reaching deal with Nigeria's United Bank for Africa, to co-fund infrastructure and energy projects in Africa. CDB only recently acquired just under 3 per cent of Barclays. That deal's main aim (apart from financing the UK bank's sweetened, but unsuccessful, offer for ABN Amro) was to improve Barclays' access to China. But it was also supposed to help it mine the increasingly rich seam of commercial activity between China and Africa.

The UBA deal doesn't seem to infringe the CDB-Barclays arrangement. CDB agreed not to enter into a similar collaboration "with another major banking institution with global operations" - a title to which UBA, with branches in Nigeria and Ghana, can only aspire. Barclays has no direct presence in Nigeria and the part of its CDB deal most relevant to African business relates to co-operation on commodities products, rather than infrastructure investment. The direct shareholding and the (as yet unconsummated) agreement that CDB will appoint a director to Barclays' board give the Barclays-CDB link backbone that the UBA-CDB venture lacks.