PaineWebber Inc. said heavy activity by investors...

PaineWebber Inc. said heavy activity by investors pushed its earnings to record levels for the fourth quarter and full year.

The brokerage said it earned $46.97 million, or 96 cents per share, in the last three months of the year, up from a loss of $92.3 million, or $2.64 per share, a year earlier. A $95.5-million restructuring charge accounted for the 1990 loss. Revenue rose 43% in the fourth quarter to $585 million from $409 million a year earlier. For the full year, the brokerage reported earnings of $150.7 million, or $3.15 per share, contrasted with a loss of $57.3 million, or $2.16 per share, in 1990.