American Stores Co. reports fiscal fourth-quarter earnings of $86 million, or $2.49 a share, up nearly 62 percent compared with $53.1 million, or $1.61 a share, in the year-ago quarter.

Sales in the 13-week 1990 fourth quarter, which ended Feb. 3, were $5.7 billion compared with $6.1 billion for the 14-week fourth quarter ended Feb. 2, 1990.The Salt Lake City-based grocery and drug store chain reported net earnings for the year increased more than 54 percent, to $182.4 billion, or $5.28 a share, compared with $118.1 million, or $3.45 a share, in fiscal 1989.

Sales for the 52-week year ended Feb. 2 amounted to $22.2 billion compared with $22.0 billion for the 53-week year ended Feb. 3, 1990.

The better-than-expected performance sent American Stores stock soaring. American stores closed at $75.50, up $4.875 in trading Monday on the New York Stock Exchange.

There were no preferred dividends in 1990, compared to preferred dividends of $8.6 million in fiscal 1989.

American Stores' principal grocery and combination store operating subsidiaries include Acme Markets Inc., Jewel Food Stores, Star Market, Skaggs Alpha Beta Inc., Jewel Osco, Lucky Stores Inc. and Alpha Beta Co.