Egypt's biggest listed bank, CIB , said on Wednesday that first-quarter consolidated net income rose 30 percent from a year earlier to LE658 million ($94.4 million) as its interest margin widened.

Revenue rose by an annual 40 percent to LE1.61 billion. Deposits grew by 9.3 percent during the quarter to LE86.1 billion, while lending rose 3 percent to LE45.7 billion.

Egyptian banks have kept their bottom lines growing thanks partly to high interest rates paid by the state last year for its short-term borrowing.

A 50 basis-point increase in the central bank's corridor rates helped the bank increase its net interest margin to 5.25 percent from 4.51 percent a year earlier.

State borrowing costs soared as foreign investors exited the local treasury market, tax receipts suffered from a weak economy and the government boosted spending to meet popular demands for better living standards after an uprising against President Hosni Mubarak in 2011.

Ratings agency Standard and Poor's cut the credit ratings of four Egyptian banks including CIB on Tuesday to CCC+ from B-, saying they held a large amount of government debt and faced significant risk as the government's likelihood of meeting fiscal targets deteriorates.