The World Bank encourages bilateral aid agencies and official export credit and banking institutions to link their financing with the Bank's. It depends largely on the borrower what type of partner is involved with the World Bank in a particular case. Lenders able to offer concessional terms are the main cofinancing sources for poorer countries while commercial banks and official export credit agencies normally act as cofinanciers for creditworthy developing countries. Although in the 1980s it was only a small proportion of lending, export credit cofinancing may play a bigger role in the future, given the constraints on official aid and the caution with which commercial banks are approaching increased international exposure. The systematic approach developed by the World Bank aims to help borrowers secure export credits in larger volumes and possibly on better terms and it is also developing cofinancing arrangements with commercial banks.