Shares in Tower Semiconductor (NASDAQ:TSEM) plunged over 11% in pre-market Wednesday after Intel Corporation (NASDAQ:INTC) confirmed it has mutually agreed with the former to terminate their previously disclosed takeover agreement.

The merger, which was announced on February 15 last year, saw Intel pay $5.4 billion for Israel-based Tower.

Intel attributed the termination to the challenges of securing timely regulatory approvals.

“Our foundry efforts are critical to unlocking the full potential of IDM 2.0, and we continue to drive forward on all facets of our strategy,” said Pat Gelsinger, CEO of Intel.

“We are executing well on our roadmap to regain transistor performance and power performance leadership by 2025, building momentum with customers and the broader ecosystem and investing to deliver the geographically diverse and resilient manufacturing footprint the world needs. Our respect for Tower has only grown through this process, and we will continue to look for opportunities to work together in the future.”

Intel shares are flat in early Wednesday trade.