Silicon Valley veteran Ray Lane has quit his post as chairman of Hewlett-Packard's board of directors, following mounting pressure from shareholders. 

Lane narrowly won re-election to the board at HP's annual shareholder meeting last month, but said yesterday that he would step down as chairman to "reduce any distraction from HP's ongoing turnaround".

In early March, Insitutional Shareholder Services, which represents the interests of many HP shareholders, demanded Lane's departure over his failure to vet acquisitions properly, including HP's $11.7 billion purchase of UK software giant Autonomy. 

Lane, who will stay on HP's board, will be replaced as chairman by Ralph Whitworth, CEO of a hedge fund with a large holding in HP, on an interim basis. 

"From here we will continue to recruit outstanding directors, strengthen our governance and do the best we can—the best we know how—for stockholders," Lane said in the statement. "Meg is leading a Herculean turnaround, so most of all, we must build and maintain the best possible leadership structure for Meg and HP's entire team to succeed."

Lane, who is also a partner at Silicon Valley venture capital firm Kleiner Perkins,  joined HP in 2010 at the same time as former SAP CEO Leo Apotheker. Apotheker was ousted in 2011 as the company's share price plummeted. 

Lane was previously co-president and chief operating officer at Oracle. He was reported to have left the software giant after falling out with CEO Larry Ellison.