The principal foreign investment is in the oil sector. Foreign private investment is officially encouraged in certain areas—such as industry, agriculture, and fishing—through an initial five-year tax exemption, which may be renewed for another five years. Foreign participation in a local company cannot exceed 65% (this also applies to the sharing of profits). Companies holding commercial agencies must also have at least 51% Omani participation. In 2002, the largest foreign investor was Royal Dutch Shell Oil, which holds a 34% of the shares of the state oil company, Petroleum Development Oman, and 30% of Oman Liquid Natural Gas. Other investors in the oil industry include Occidental Petroleum, Hapex, Amoco, and Elf Aquitaine. The Sultanate does not publish estimates of inbound and out-bound investment Foreign investment in the Muscat Securities Market (MSM) has averaged 15% to 16%, but has dropped in absolute terms. In December 1999, foreign investment in the MSM was $867.8 million. A year later this had fallen to $730.5 million, and at the end of May 2001, foreign investment in the SMS was $708.9 million. No systematic information is available on foreign direct investment (FDI).