A month after taking an 8.76% stake in SPX (NYSE:SPXC), an industrial equipment manufacturer, Relational Investors disclosed in a 13D filing with the SEC that it has upped that position to 9.9%.

Relational previously said it believed the business remained attractive, but that a "growth at any cost" strategy had destroyed shareholder value and the company was in need of change. The investment firm is looking to increase operating margins by accelerating the speed with which it divests underperforming assets, establishing rigorous capital allocation disciplines, and properly aligning executive compensation and shareholder value creation.

SPX had attempted to buy Gardner Denver (NYSE:IR) for $4 billion in December, but no deal ever emerged. Because the size of the transaction would have exceeded even SPX's market cap at the time, Relational Investors, which wasn't a shareholder at the time, was motivated to intervene because of the company's pursuit of acquisitions that it believed harmed shareholder value.

If SPX can't achieve those goals and become valued at least as well as its peers, then Relational says it ought to pursue strategic alternatives, which is often a euphemism for putting the company on the market for sale.

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