Asked about the prospect of Scottish independence, the oil services tycoon declined to elaborate on a statement in which he said both sides in the debate must try to assure stability for the medium term.
On the subject of whether the wait for the outcome of the planned independence referendum in Autumn 2014 could deter investment in the North Sea, Sir Ian told The Herald: "That's a separate issue. It's really important that both sides and the UK genuinely understand that the oil and gas industry is in for a fragile four or five years. We need to keep investing while the infrastructure is in place."
Noting that investment has been increasing, he added: "Both sides must be aware that if this industry becomes a political football and people can't get the confidence that there will be continuity the momentum will be changed."
Speaking a week after retiring from the board of Wood Group following 45 years at the helm of the Aberdeen-based firm, Sir Ian welcomed the concessions made by the Chancellor since he hiked the tax on North Sea profits in 2011.
He said the UK Government now appears to understand the importance of maximising the recovery of the North Sea's reserves rather than just treating the industry as a source of cash.
However, he complained the industry has had scant recognition for the "huge contribution" it has made to the UK.
Sir Ian said the industry could generate $2500bn to the UK economy over the next 20-30 years, at $100 per barrel oil if recovery rates are maximised.
The businessman reiterated support for plans to redesign Aberdeen's Union Terrace Gardens, for which he offered £50 million backing. These were rejected by the city council in August.
He received a lifetime achievement award from Oil & Gas UK last night.