Underground Partners

FOR THE PAST YEAR, SCORES OF WILDCATTERS AND would-be oil barons have been looking for ways to capitalize on the legendary oil reserves in the Commonwealth of Independent States. But when mighty Chevron signed an agreement with Kazakhstan last week to develop the Tengiz field, one of the world's largest, it marked the biggest partnership to date between a U.S. corporation and a former Soviet republic. The plan calls for the partners to invest $20 billion in the venture over the next 40 years. Chevron will have a 50% interest, but Kazakhstan will get 80% of the income, after the U.S. oil company pays taxes and royalties on its share. The region could eventually produce as much as 9 billion barrels of oil, which would help boost the output of the former Soviet Union. Last year, overall C.I.S. production fell 12%. The deal was nearly three years in the making, and operation is expected to begin early next year. Chevron's step could induce other large U.S. corporations to invest in the politically fragile area.