An investigation on behalf of investors of Keithley Instruments, Inc. (NYSE:KEI) over potential breaches of fiduciary duty by the Keithley board of directors in connection with the proposed takeover of Keithley Instruments, Inc. (KEI) by Danaher Corporation was announced.

The investigation by a law firm concerns whether Keithley Instruments and its Board breached their fiduciary duties owed to Keithley Instruments investors in connection with the proposed takeover.

On Wednesday, September 29, 2010, Keithley Instruments, Inc. (NYSE: KEI) and Danaher Corporation (NYSE: DHR) announced that they have entered into a merger agreement, which has been unanimously approved by the Keithley Instruments Board of Directors, pursuant to which Danaher Corp. will acquire all of the outstanding Common Shares and Class B Common Shares of Keithley Instruments, Inc. at a purchase price of $21.60 per share in cash for an enterprise value of approximately $300 million net of cash to be assumed.

But the investigation by a law firm concerns whether the sale process and the offered price are unfair to the shareholders of Keithley Instruments, Inc. (NYSE:KEI). Even though shares of Keithley Instruments (KEI), which traded at roughly $12 per share, jumped by 72% to $21.45 per share after the announcement, a partnership affiliated with Joseph P. Keithley has already agreed to vote a number of Class B Common Shares representing 19.99% of the voting power of Keithley Instruments in favor of the merger. Therefore the investigation concerns whether Keithley Instruments Board of Directors breached their fiduciary duties to Keithley Instruments, Inc. (NYSE:KEI) stockholders by failing to adequately shop Keithley Instruments, Inc. before entering into the transaction.