Cameroon has hiked its debt issuance for 2015 to 900 billion CFA francs ($1.56 billion) from 320 billion initially planned, a decree signed by President Paul Biya said, amid a shortfall in oil revenues due to the slump in global oil prices.

The decree signed on Friday authorised the government to "issue debt including Treasury bills and bonds of up to 900 billion CFA francs to finance development projects."

It did not give any further details, but state newspaper Cameroon Tribune said on Monday that a fall in oil prices had forced it to revise its borrowing needs. Oil is Cameroon's top revenue earner, contributing about 20 percent to the budget.