Andover, MA – MKS Instruments, Inc. has entered into a definitive agreement to acquire the ENI division of Emerson Electric Co. Under the terms of the agreement, MKS will issue 12 million shares of common stock, valued at $251 million, in exchange for the businesses and assets of ENI. MKS will also assume approximately $3.5 million of net debt. ENI’s products complement that of MKS’ ASTeX Products group, adding power conversion technology to MKS’ capability in plasma management. MKS is a supplier of gas measurement, control and analysis products used in the semiconductor and other advanced thin-film manufacturing processes. ENI supplies and instruments used in chip production.