Semiconductor equipment maker Lam Research said on Wednesday it had terminated a $10.6 billion deal to buy rival KLA-Tencor.

The companies decided against the merger due to antitrust concerns raised by the Department of Justice, according to a statement from KLA-Tencor.

Lam Research agreed to buy KLA-Tencor for $67.02 per share last year, amid a wave of consolidation in the chip industry.

Together, the companies would have commanded a 42% share of the wafer fabrication equipment market.

KLA-Tencor and Lam Research said in August that regulatory clearance for the deal may be delayed beyond Oct. 20.

KLA-Tencor also raised its quarterly dividend by 2 cents to 54 cents per share.

Shares of KLA-Tencor klac were down 5.8% in extended trading, while Lam Research’s shares lrcx fell 2.7%.