Mr Cook is also waiving his entitlement to a pounds 1.5m "golden parachute" - described by him as a "pittance" - and abandoning a generous bonus scheme that doubled his basic pay.
Details of Mr Cook's revised contract are contained in an offer document sent out yesterday to shareholders by Steel Castings Investments, the buyout vehicle backed by venture capital group Electra Fleming.
It shows that Mr Cook will be paid an annual salary of pounds 200,000 if the buyout succeeds. In return, he will swap his 4.6 per cent stake in William Cook worth pounds 3.7m and reinvest it by taking a14 per cent holding in Steel Castings. Electra Fleming will own 78.5 per cent of the new company, while 20 senior managers of William Cook are also investing.
"Mr Cook's interests and those of Electra Fleming will be properly aligned," a spokesman for the buyout group said.
Steel Castings' cash offer of 425p a share values William Cook at about pounds 80m and tops Triplex Lloyd's cash and shares offer worth 384p last night.
Corporate governance and Mr Cook's salary has formed the centrepiece of Triplex Lloyd's attack on William Cook. Triplex has still to decide whether to raise its bid for a second time.
The posting of the offer document means the 60-day bid timetable clock begins ticking again William Cook's shares are tightly held with just half a dozen institutions owning about two-thirds of the company.