May 2, 2001 2:27 AM

Despite the opening of Pinnacle Entertainment’s new Indiana riverboat casino, the company reported a net loss of $2.1 million, or 8 cents per diluted share, for the first quarter.

The Belterra Casino Resort opened for business on the Ohio River in the fourth quarter, bringing in $26 million in new revenues and helping boost revenues 22 percent company-wide compared with the same period last year.

On the down side, increased gaming taxes in Louisiana, combined with poor weather and increased competition, drove down earnings at Casino Magic Bossier City and Casino Magic Biloxi. Combined with the effects of the sale of Boomtown Biloxi, Casino Magic Bay St. Louis and the Turf Paradise Race Track, the result was a decline of $18.6 million in pre-tax earnings.

In addition to the Boomtown and Casino Magic casino brands in Louisiana, Mississippi and Reno, Nev., the company owns a casino in Argentina and receives lease income from two card clubs in the Los Angeles area.

Elsewhere, Monarch Casino & Resort, owner of the Atlantis Casino Resort in Reno, reported a 6.8 percent increase in first quarter net revenues, from $22.6 million in the first quarter of 2000 to $23.7 million. Net income jumped from $93,204 to $302,311, representing an increase from 1 to 3 cents on a diluted per-share basis.