The battle for control of the computer manufacturer, Dell, is practically over.
Billionaire and activist investor Carl Icahn is abandoning his attempt to block a private equity buyout of the US computer company, but still argues the plan "greatly undervalues" the company.
It now leaves the way clear for Dell's founder, Michael Dell, to take over.
In a lively letter posted on Tuesday, Mr Icahn said that he was incensed, and blamed rigged shareholder voting rules for his withdrawal.
He was referring to a change which meant that only votes cast would be tallied, making the approval process easier. Shareholders not voting will no longer be counted as "no" votes.
The BBC's reports that the PC maker has been under pressure as consumers shift away from traditional computers. Mr Dell has pledged to shift the business away from PCs into mobile devices and business software.
His bid to take his company private includes an offer of $13.75 per share plus a 13 cent dividend.
Under Mr Dell's plan shareholders will be bought out and the company removed from the stock exchange.
He argues that it will be easier to reinvigorate Dell without the pressure of shareholder scrutiny.