The semiconductor book-to-bill ratio fell in April.

The ratio, a key indicator of the health of the semiconductor industry, stalled after a modest three-month rise, according to figures released by the Semiconductor Industry Assn. The ratio, which compares new orders to shipments, dropped to an estimated 0.77 for April, down from a revised figure of 0.80 for March. Those levels are still far below the 1.53 recorded in January, 1984, and reflect a continuing recession in the industry.