SAN FRANCISCO — Global billings by North American semiconductor equipment suppliers declined on a sequential basis in September for the fourth straight month in what the SEMI trade association described as a typical third quarter lull.

The three-month average of fab tool billings in September was $2.09 billion, up 1.8% from September 2017 but down 6.5% compared to the final August billings level of $2.37 billion, SEMI said.

Since peaking in May at $2.7 billion, monthly equipment billings have declined by 23%. However, 2018 tool billings remain well ahead of last year's record pace.

Semiconductor equipment billings in billions of dollars

“Quarterly global billings of North American equipment suppliers experienced their typical seasonal weakening in the most recent quarter,” said Ajit Manocha, SEMI's president and CEO, in a press statement. "Relative to the third quarter, we expect investment activity to improve for the remainder of the year.”