Also, Chevron said its domestic petroleum operations earned $96 million, compared with $134 million in the fourth quarter of 1987.

The company had revenues of $955 million in 1987, with 93 percent coming from petroleum operations.

For the full year, Mobil's earnings from petroleum operations were $522 million lower, reflecting a large decline in refining and marketing results.

It is a key area for the country's petroleum operations.

Income from petroleum operations outside the United States increased to $167 million, from $136 million a year ago.

Earnings attributed to petroleum operations rose 63 percent, to $322 million, as a result of a 15 percent increase in sales and higher prices.

Natural gas and petroleum operations were regulated by law No. 05-07 of April 28, 2005.

In 1970, Charter purchased a petroleum operation for $70 million from the Signal Companies.

"We are obviously not satisfied with the level of earnings from our petroleum operations," he said in the report.

The latest year also includes an expense of $130.6 million in impairments in petroleum operations during the third quarter.