More flights and lower fares continued to lure travelers to Baltimore-Washington International Airport in June, setting yet another monthly record with 1.1 million passengers.

While discount fares are likely to start cropping up at other airports -- including BWI's competitor, Washington Dulles International Airport -- growth here showed little sign of slacking off.

For the first half of 1994, nearly six million passengers traveled through the state-owned BWI, up 39.6 percent over the same period last year. By comparison, the average six-month increase in passengers at all U.S. airports was 6.2 percent.

The surge also reversed a two-year downturn in international traffic. Charter flights carrying World Cup Soccer fans headed for Robert F. Kennedy Stadium in Washington helped push BWI's international traffic up 35.4 percent in June, and up 15 percent for the first half of the year.

Traffic has been growing dramatically at BWI since last fall when fare wars broke out after the no-frills, low-priced Southwest Airlines announced it would start its first East Coast service there.

Theodore E. Mathison, BWI's administrator, yesterday predicted the growth would continue in the near future although perhaps not at the levels it has for the past six months. Ultimately, he said, other airports will start sharing in the passenger boom as low-fare operations spring up elsewhere. "At some point down the road, as more and more low-fare operations come into being, we're going to see more of a level playing field," he said.

In October, United Airlines will begin its new low-fare service on the West Coast. That will likely spread to Dulles where United is a major carrier.