The Nevada Gaming Control Board reported Friday that gamblers lost a record $1.85 billion to Nevada casinos in 1978, a year of major casino expansion.

Despite an unusually harsh winter, the gaming commission reported that the gambling business thrived and paid $96.5 million in state taxes.

Gross revenues by casinos rose 21.5 percent over 1977. These revenues represent earnings before taxes and business expenses were deducted.

The gaming board said net profits for casinos will average about 7 percent of the gross after all deductions and costs.

According to gaming board member Jack Stratton, the record gross figure "doesn't necessarily mean the profits are going up as fast. The costs of casinos are going sky-high and profits are certainly not increasing in the same degree as the growth."

Although profit figures of individual casinos are confidential, the state gave a breakdown of revenue figures in areas of the state.

Stratton said that while Las Vegas accounted for $1.2 billion of the take (up 21.7 percent over 1977), the overall statewide increase was primarily fueled by heavy casino expansion in the Peno, Sparks and North Lake Tahoe areas.

The Reno-Sparks area reported $367.4 million in 1978 winnings, up 31 percent over 1977.

Meanwhile, casinos in the South Shore area of Lake Tahoe grossed $168.7 million in 1978 gambling revenues, up 4.1 percent over 1977. Carson City clubs jumped 17.5 percent to $26.4 million in revenues. The remainder of the revenues were collected from casinos in other areas.

The total statewide take for the final quarter of last year amounted to nearly $460 million, 21 percent more than the same period in 1977 -- the sixth consecutive quarter with an increase of 20 percent or more.