* Twentieth Century Industries said its fourth-quarter...

* Twentieth Century Industries said its fourth-quarter earnings fell almost 50% to $19.7 million, or 39 cents per share, from $39.6 million, or 77 cents per share, a year earlier. Revenue for the three months ended Dec. 31 was up 12% to $237.4 million from $210.1 million in 1990.

The company attributed the lower fourth-quarter earnings to more weather-related claims and the effect of the Oakland fire.

For the year, the Woodland Hills-based insurance holding company posted net income of $103.5 million, or $2.02 per share, on revenue of $906.8 million. This compares to earnings of $98.7 million, or $1.92 per share, on revenue of $799.6 million in 1990.

Company founder and Chairman Louis W. Foster characterized the 1991 performance as robust. He reported that total policies rose 14%. In auto insurance, assigned-risk policies fell to 11,000 automobiles from 43,000 a year ago.