Higher natural gas prices and generally stronger...

Higher natural gas prices and generally stronger chemical results helped offset tighter profits from gasoline and other refined products to lift results at the country’s big oil companies in the final three months of the year.

Los Angeles-based Atlantic Richfield Co. reported a 12% increase in fourth-quarter earnings, well above many analysts’ expectations, as higher oil prices and lower expenses offset increased exploration costs. Arco reported net income of $348 million, or $2.13 a share, up from $311 million, or $1.90, a year earlier.

Exxon Corp., the country’s largest oil company, said it earned $1.68 billion, or $1.35 per share, compared with $1.9 billion, or $1.53 per share. Mobil Corp. earned $775 million, or $1.93 per share, compared with $523 million, or $1.28 per share. Amoco Corp. adopted a new accounting rule in the fourth quarter, resulting in quarterly earnings of $207 million, or 42 cents a share, compared with $536 million, or $1.08 a share, a year earlier.

Texaco Inc. recorded a charge to accommodate a new accounting rule that resulted in a fourth-quarter net loss of $251 million, or $1.02 per share, contrasted with earnings of $399 million, or $1.49 per share. Without special items such as the accounting charge, the company earned $367 million in the fourth quarter, up from $288 million.