Executives at a broad range of businesses are fairly optimistic about the economy's prospects for improvement, according to a survey.

The Conference Board, a business-funded research organization, said a poll of about 500 top executives regarding the 1992 final quarter revealed that 70 percent believe the economy will improve in the coming six months while only 8 percent expect conditions to worsen.The board's measure of business confidence edged down one point to 61, though a reading above 50 generally indicates "a surplus of positive responses."

"The current reading is still relatively high," said Jason Bram, an economist with the Conference Board. "Moreover, the latest survey returns were a bit more upbeat than earlier ones, suggesting a renewed upswing in confidence within the quarter."

Executives in all major businesses were hopeful about prospects for their own industries, with retailers and wholesalers in particular expressing optimism about the critical holiday shopping period.

Forty-three percent of those polled said conditions in their own industries have improved in the past six months. That's down from 48 percent in survey conducted in the third quarter.

Among the 21 percent of executives who say conditions have weakened in their industries were representatives from the manufacturing sector, particularly non-durable goods makers. Durable goods are items such as appliances designed to last more than three years.

Inflation expectations are modest, with most executives anticipating an average rise of about 2.6 percent, the Conference Board said. Insurance and utilities executives said they expect the largest price increases.