Ford Motor Co. earned $1.623 billion in the first quarter of 1988, setting a world auto industry record for earnings in a single quarter, the nation's second-largest automaker said Thursday.

Ford's earnings of $3.31 a share on sales of $20.74 billion were up 8.8 percent over first-quarter 1987 earnings of $1.49 billion, or $2.87 a share, on sales of $18.14 billion.The previous quarterly earnings record was set by General Motors Corp., the world's largest automaker, with $1.614 billion in profits in the first quarter of 1984.

Ford profits earned in the United States fell 10.2 percent in the first quarter to $1.04 billion from $1.16 billion in first-quarter 1987. But the drop was offset by record overseas earnings, which jumped nearly 76 percent to $580 million from $330 million in the first three months of 1987, Ford said.

"Our first-quarter earnings reflect the good balance of the overall Ford team effort," Chairman Donald E. Petersen and Vice Chairman Harold A. Poling said in a joint statement.

"With increasingly competitive worldwide automotive markets, Ford must continue to improve quality and operating efficiency, as well as offer customers good value in products," they said.

In 1987, Ford set a world industry earnings record for a single year with a profit of $4.63 billion, and was the top-earning U.S. automaker in 1986, earning $3.29 billion.

Ford blamed the drop in U.S. earnings on the costs of introducing new products and running buyer incentive campaigns.