By Christopher Alessi and Natascha Divac, Dow Jones Newswires:  Siemens AG’s planned acquisition of automation and industrial software provider Mentor Graphics Corp. is the German giant’s latest play to stay competitive in the race to digitize heavy industry.

Siemens on Monday offered $37.25 a share in cash, equivalent to a 21 percent premium on Mentor’s closing share price on Friday, giving the U.S. company an equity value of around $4 billion.Wilsonville, Ore.-based Mentor, which has agreed to the acquisition, sells software and hardware design-automation tools for the development and testing of advanced electronic systems. The company has a field office in Longmont. Mentor’s shares gained 18.3 percent to $36.30 in recent Nasdaq trading on Monday.

“It’s a perfect portfolio fit to further expand our digital leadership and set the pace in the industry,” Siemens CEO Joe Kaeser said.  Cont'd...