Nigeria, Oct. 27 -- Guaranty Trust Holding Company (GTCO) reported a 12.2 per cent decline in net profit for the nine months to September, compared to the corresponding period of last year, as mounting costs strained earnings, its unaudited accounts issued on Tuesday showed.

The financial services group posted an improvement in interest income, its major source of revenue, but faced increased pressure from interest expense, which jumped 27.7 per cent year on year.

Interest expense as a percentage of interest income stood at 27.6 per cent, relative to 22.6 per cent a year ago.

Consequently, net interest income, which implies the difference between the cash generated by banks and financial institutions on interest-bearing assets and what...