The banking system had worked effectively until the late 1970s and 1980s, when the decline in foreign trade, balance-of-payments problems, spiraling external debt, increased corruption, and the introduction of Islamic banking disrupted the financial system. Some reforms were introduced in the IMF economic adjustment program, but further reform of the system was an important consideration while developing the January 2005 Comprehensive Peace Agreement to end the civil war in Sudan. One of the decisions at that time was that Sudan would have a dual banking system. As a result, the North retained an Islamic banking system, whereas the South adopted interest-based banking. In 2005 the GOSS created a central bank, the Bank of South Sudan, which functioned as a branch of the Bank of Sudan and shared its monetary policies. Several foreign banks established branches in Juba.