SAN JOSE — North America-based semiconductor equipment manufacturers today reported the June 90-day average bookings fell 9.8% from the revised May figures to $1.46 billion.

Bookings were down 5.5% from June 2011, the SEMI trade group said. The companies surveyed posted $1.55 billion in billings worldwide in June, up 1% from final May levels and down 5.2% from last year.

The book-to-bill ratio was 0.94 in June, meaning that $94 worth of orders were received for every $100 of product billed for the month. Semiconductor fabrication equipment is considered a leading indicator for future printed circuit board and electronics assembly orders.

The drop broke a streak of seven months of increases.