At a special meeting held at the Sigma-Aldrich Life Science and Technology Center in St. Louis, Missouri, USA, 78% of the company's shareholders approved the planned takeover by Germany's Merck KGaA for $17 billion in cash. The Sigma-Aldrich board of directors had previously unanimously approved the deal.

Under the agreement announced on Sept. 22, 2014, Merck will acquire all of the outstanding Sigma-Aldrich shares for $140 per share in cash. A Merck shareholder vote is not required.

The Darmstadt-based chemical and pharmaceutical producer said it continues to expect to close the transaction, which is still subject to regulatory approvals, in mid- 2015. It said it is "is working closely with authorities to ensure a seamless transaction."

Merck said the acquisition is a key element in its "Fit for 2018" transformation and growth program aimed at strengthening its healthcare, life science and performance materials platforms.

The merger of Sigma-Aldrich and Merck's laboratory chemicals offshoot Merck Millipore would be able to offer the Laboratory & Academia sector a complementary range of products across laboratory chemicals, biologics and reagents.

In pharma and biopharma production, Merck said Sigma-Aldrich would complement Merck Millipore's existing products and capabilities with additions along the entire value chain of drug production and validation.