CSX Corp. of Richmond, the parent company of the merged Chessie System Inc. and Seaboard Coast Line Industries Inc., yesterday reported that second-quarter earnings were cut in half, mostly by the coal miners' strike.

The company said the strike's impact was offset partially by a strong showing in realty income and good earnings from its Florida Publishing Co. and Greenbrier operations.

Earnings were $37 million (90 cents a share) compared with $75.9 million ($1.94) a year earlier. Transportation revenue was $1.2 billion compared with $1.1 billion, and nontransportation revenue was $93.9 million compared with $96.8 million.

Earnings for the past six months were $124.8 million ($3.04) compared with $131.0 million ($3.35). Revenues were $2.6 billion compared with $2.4 billion.

The company called its six-month earnings "strong" . . . in the face of the 80-day coal miners' strike. The strike reduced coal traffic for CSX rail units by more than 10 percent from their record level a year earlier, the company said.

"We are pleased with these results," CSX Chairman Prime F. Osborn said.

Baltimore Gas and Electric Co. reported earnings of $51.2 million ($1.55 a share) compared with $37 million ($1.16) for the five months ended May 31. Revenues were $585.5 million compared with $489.3 million.

For the 12 months ended May 31, earnings were $131.5 million ($4.02) compared with $94.5 million ($2.98). Revenues were $1.3 billion compared with $1.1 billion.