General cargo volume moving through the Port of Baltimore's public terminals plunged nearly 20 percent during the first quarter of the year, according to figures released by the Maryland Port Administration.

Officials said the precipitous decline from the first quarter of 1989 reflected the three-day port-wide work stoppage in January, the labor turmoil and uncertainty that followed and a national drop in export steel and import auto movements.Indeed, steel shipments decreased a startling 82 percent to 35,000 tons

from over 198,000 tons and auto shipments slipped a hefty 28 percent from the figures posted in the first three months of 1989.

High-value container cargo, by far the largest single general cargo category moving through MPA terminals, dropped 9 percent, by over 88,000 tons, in the quarter.

Total general cargo volume for the quarter was 1.18 million tons, compared with nearly 1.5million tons during the first quarter of 1989.

"These figures don't come as a surprise," said Richard H. Trainor, Maryland secretary of transportation and chairman of the policy-setting Maryland Port Commission.

"We had our share of problems earlier this year, but from all indications, the port is on its way back. We believe steamship lines and shippers have confidence in the port," he said.

J.C. Shay, a port spokesman, said the statistics were "down, predictably, but there are some encouraging trends."

Those trends occurred during the latter part of the quarter, and indicate that cargo levels are increasing, said port officials. They said container traffic in March increased slightly, making it the best month for that category in a couple of years.

The port administration released a separate set of volume figures showing a 7.5 percent annual increase in total foreign commerce through all of Baltimore's public and private facilities in 1989.

According to the U.S. Census Bureau's foreign trade division, Baltimore handled nearly 31 million tons of foreign commerce valued at $18.4 billion last year.