The 1973 investment code guaranteed the free transfer of capital, normally earned profits, and funds resulting from sales of foreign companies. According to legislation adopted in 1982, reduced import duties and taxes are offered on production equipment and profits on manufacturing and trading are tax exempt for the first five years. However, in view of the Congo's fragile economy, banks required a public guarantee before investing their funds. A new investment code enacted in 1992 and amended in 1996 legislates equal treatment for domestic and foreign investors.
In 1994, the regiment for participation by foreign oil companies was changed from the joint ventures that had prevailed since 1968 to production sharing agreements (PSAs), by which foreign oil companies operate under contracts with the national oil company, SNPC. Plans were announced in 1995–96 to privatize state-owned enterprises in the oil distribution, oil refining, telecommunications, rail and water transportation, electricity, and water distribution sectors designed to attract foreign investment.
In June 1997, the United States and Congo concluded a bilateral investment treaty (BIT). That month, the outbreak of civil war brought most privatization initiatives to a halt. The flow of foreign direct investment (FDI) was a negative divestment of an estimated -$11.9 million in 1997. Despite renewed violence in 1998 and 1999, privatization of some upstream and downstream operations of Hydro-Congo increased FDI inflow to $117.8 million and $134.6 million, respectively. A fragile peace accompanied by an IMF-directed austerity program in 2000 helped produce a negative outflow of FDI of -$75.2 million. For 2001, FDI inflow was estimated at a modest $59.1 million.
Virtually all foreign investment in the Republic of Congo has been in the oil and timber sectors, with the French company Total FinaElf historically dominant in the oil sector, which in turn historically dominates the economy. The second largest oil investor has been ENI-Agip (Agip-Congo) of Italy. US oil companies that have investments include Anadarko, Chevron Texaco, CMS-Nomeco, Exxon-Mobile, and Marathon. Other foreign oil participants are Royal Dutch Shell (United Kingdom), Energy Africa (South Africa), and Heritage Oil (Canada). Most of the oil industry is not only an enclave, employing mostly foreign personnel, but offshore. Investment in the wider economy continues to be hampered by numerous factors even apart from political turmoil, including a poorly developed financial sector; an inadequate and war-damaged infrastructure; high labor, transportation and raw material costs; low productivity; and militant labor unions.