SAN JOSE – The 90-day average bookings at North America-based semiconductor equipment manufacturers fell nearly 35% year-over-year in August amid uncertainties over demand.

The three-month average worldwide bookings in August was $1.18 billion, down 8.8$ sequentially and down 34.8% from 2010. Billings fell 3% from July and 5.1% from last year to $1.48 billion.

The book-to-bill ratio was 0.80, according to SEMI. A book-to-bill of 0.80 means that $80 worth of orders were received for every $100 of product billed for the month.

“Weaker DRAM demand, foundry spending reductions and near-term uncertainties about electronics demand are reflected in declining sales trends for new semiconductor manufacturing equipment,” said Stanley T. Myers, president and CEO of SEMI.  “Consequently, the average billings are at levels last seen in June of 2010.”

The SEMI book-to-bill is a ratio of three-month moving averages of worldwide bookings and billings for North American-based semiconductor equipment manufacturers. Billings and bookings figures are in millions of U.S. dollars.

Source: SEMI September 2011