Gershon's successor will be closely involved in the government's Common Systems Strategy, which aims to standardise IT across Whitehall, according to advertisements for the £145,000, three-year, fixed-term contract.
The new OGC chief will preside over the government's Gateway Review process, introduced by Gershon to impose best-practice project management on government IT programmes, and continue the drive to win better deals from IT suppliers.
Last year Gershon spearheaded the first public sector-wide software licensing deals with Microsoft, IBM/Lotus and Sun Microsystems. These were followed by deals with Oracle and Orange.
Bob Griffith, international secretary at public sector IT managers organisation the Society of IT Management, said Gershon's impact spread beyond his central government brief.
"Peter Gershon has changed the culture of Whitehall," said Griffith. "The Microsoft deal was a good one because it widened the opportunities open to local government."
The OGC is expected to announce in the next few weeks that it has exceeded its savings target.