Broadcasting giant CBS Inc.’s first-quarter net income...

Broadcasting giant CBS Inc.’s first-quarter net income dropped 20% because of a large one-time gain in the year-ago quarter, but its operating results soared.

CBS earned $18.6 million, or $1.20 a share, down from $23.3 million, or $1.21, a year earlier. But its operating results jumped 79% from the $10.4 million it earned from first-quarter operations in 1991.