The Central Bank of Nigeria has mandated banks to limit their total outstanding exposures to all tiers of government and their agencies at any point in time to 10 per cent of their total credit portfolio.
CBN pegs loans to govt at 10 per cent (http://thenationonlineng.net/web2/articles/46764/1/CBN-pegs-loans-to-govt-at-10-per-cent/Page1.html)