Thermo Fisher Scientific, the world's largest maker of scientific instruments, said it would buy FEI for about $4.2 billion to gain access to the company's electron microscopy technology that helps studying proteins.
The $107.50 per share offer represents a premium of 13.7 percent to FEI's Thursday close of $94.58. FEI shares rose to $107 in premarket trading on Friday.
FEI designs, manufactures and supports high-performance electron microscopes that provide images and information at micro, nano and picometer scales which are used by life sciences companies to make discoveries.
The electron microscopy platform complements Thermo Fisher's mass spectrometry systems which help identify the chemical constitution of a substance.