Mr Cochrane said he supported the stance of SSE, formerly known as Scottish & Southern Energy, which last week warned it was having to take account of the uncertainty around Scotland's future when making investment decisions.
Mr Cochrane said: "I think the most important thing is that there is certainty, both as to the process and to ensure there is a clear-cut result, irrespective of what that result might be. Secondly, there needs to be greater clarity around what the proposition put to voters is. As a business person who lives and works in Scotland, and has for my entire career, I agree with the sentiment SSE presents."
The Scottish Government is looking at a vote in the autumn of 2014 but has come under pressure from opposition parties, Westminster Government and business lobby groups to move it to 2013.
Asked whether Weir Group, which has a market value of £4.5 billion, would have to reconsider the location of its headquarters, Mr Cochrane said: "We want Scotland to be successful and an attractive place to do business. Any uncertainty weighs against that and is something that should be minimised."
He added: "We need to understand what is the proposition and what would be the terms of that independent environment and I do not think anybody really knows that."
Secretary of State for Scotland Michael Moore said: "As yet another business raises serious questions about independence, it is clear that the referendum continues to cause damaging uncertainty."
Scottish finance secretary John Swinney said: "These are perfectly fair and balanced comments, and we are absolutely committed to having a fully-informed debate on Scotland's future – which is exactly why in the coming months we will continue to set out what independence means for people and business in Scotland, and in autumn 2013 we will publish the full prospectus for independence in plenty time for the referendum."
FTSE-100 listed Weir Group had a bumper year after seeing soaring demand in both its minerals business, which provides pumps to the mining industry and its oil and gas operation which has benefited from growing demand from the controversial fracking industry, in which liquids are injected into rocks at high pressure to release oil and gas.
Revenue was up 40% to £2.3bn in the year to December 30, translating into a rise in underlying profit to £396m from £295m in 2010.
Mr Cochrane said: "We have a strong platform in oil and gas and a strong platform in minerals.
"The issue now is how do we extend our product ranges and extend our routes to market to employ our strategy which is to grow faster than our end markets."
There was some concern in the City about a reduction in Weir Group's profit margins and that demand for its products could be hit by a fall in the gas price.
Weir's shares fell as much as 5.8% before closing at 2106p, a 99p, or 4.5%, drop.
Mr Cochrane said the margin squeeze was a result of revenue being weighted more to new equipment than after sales and that there was a lag before after-sales came through.
"The original equipment growth is giving us the platform for the future after market sales going forward," he said.
Weir Group suffered a blow earlier this week when Australian regulators rejected its claim that rival FLSmidth should not be allowed to increase its bid for mining equipment supplier Ludowici over which the two firms are battling.
Mr Cochrane said yesterday: "We are appealing against the decision. We will let that process run through and review our position once that has completed.
"It is an attractive opportunity," he added, but he continued: "We have set out strict financial criteria."