Gary Cohn, a former Goldman Sachs president and head of the National Economic Council under Donald Trump, has joined IBM as vice-chairman as the fading computing giant seeks to inject fresh energy into an attempted overhaul that has failed to revive confidence on Wall Street.

The appointment marks a rare injection of heavyweight talent into IBM’s top ranks from the outside, and is the first time in two decades that Big Blue has named a vice-chairman.

Though taking on an executive position, Mr Cohn will not be full time or have a formal management role. Instead, IBM said he would work “in partnership” with its leadership group “on a wide range of business initiatives and external engagements, including “business development, client services, public advocacy and client relationship management”.

Since departing the White House in the spring of 2018, Mr Cohn has helped found Cohn Robbins Holdings Corp, a publicly traded special-purpose acquisition company, or Spac, which has raised more than $800m in funds, according to Reuters. The company has not yet invested the proceeds from its listing in October of last year.

The appointment comes in the midst of a strategic revamp at IBM that has included the $34bn acquisition of open source company Red Hat, as well as a recent plan to spin out its giant managed services arm. Despite the drastic moves, IBM missed out on a powerful tech rally last year, falling even further behind Amazon and Microsoft, whose dominance of cloud computing makes them the new powers of IT.

Mr Cohn joins at a transitional moment for IBM’s management. Arvind Krishna, who took over as chief executive, is a former head of IBM research, and is seen by many analysts as a temporary holder of the top job before a transition to Jim Whitehurst, the former chief executive of RedHat and now IBM’s president.

The US computer maker last brought in a non-technology executive in a top role almost three decades ago, when Lou Gerstner, a former head of American Express and RJR Nabisco, joined as chief executive.

At the time IBM was struggling in the aftermath of the mainframe computing era. Mr Gerstner went on to revive it by turning it into the leading IT services company.