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.
The deal also allows Thermo Fisher to utilize FEI's nano-prototyping technologies to develop devices which are increasingly getting smaller and more complex.
Hillsboro, Oregon-based FEI employs more than 3,000 worldwide and generated revenue of $930 million in 2015.
Thermo Fisher said the transaction would immediately add to its earnings.
JP Morgan is Thermo Fisher's financial adviser and Wachtell, Lipton, Rosen & Katz its legal counsel.
Goldman Sachs is FEI's financial adviser and Wilson Sonsini Goodrich & Rosati its legal counsel.