The World Bank has developed a flexible oil and gas programme that is structured to meet the changing needs of the sector as they arise. The Bank became prominent in the oil and gas sector after the oil crises of the 1970s, when it began assisting client countries in developing their indigenous energy resources. At the beginning, Bank lending concentrated on exploration and development of hydrocarbon resources where the level of lending expanded to US$1 billion in 1983. This rapid expansion caused some concern that Bank activities might preempt those of the private sector. In response, the Bank imposed in 1984 strict limitations on petroleum exploration and oil production lending. In combination with the perception that future oil demand would be weak, this caused the lending programme to fall off sharply (to US$300 million by 1986). By 1990, the Bank was again moving actively into hydrocarbon sector lending, but then the emphasis was on promoting private sector development and supporting the development of natural gas as a substitute for coal and oil, Bank lending to the sector has been on the increase since 1990; a lending level of about US$1 billion yearly is expected for the second half of the 1990s. In addition to its direct lending, the World Bank facilitates contributions by other financiers through its cofinancing and risk mitigation arrangements.