Rangers owner Sir David Murray is backing First Minister Alex Salmond for a second term in office.
The long-time Unionist said Mr Salmond was the "best choice" for Scotland in the current difficult climate.
He said he still supported the Union but felt the SNP had demonstrated it could lead a competent government.
Speaking ahead of the general election last May, Sir David had said a Conservative victory would be in the long-term interests of the country.
In 2007 Sir David accused Alex Salmond of "intimidating" Scotland's business community and said independence would lead to greater taxes.
He had also warned that it could lead to anti-Scottish sentiment among business chiefs in the City of London.
On Sunday the former Rangers chairman said he remained in favour of the Union but was giving his support to Alex Salmond.
"Over the years I have been asked on numerous occasions my views on Scottish politics," he said.
"I now intend to make my present views clear, but have no intention to make any further political statement or to become involved in party politics.
"As people know, although I have never been party political, my views have always been in favour of the continuation of the Union.
"They still are. However, the SNP under Alex Salmond has demonstrated that they can run a competent government and Alex Salmond makes a fine first minister.
"I think Alex deserves a second term in office, and he is the best choice for Scotland during these difficult times."
The former Rangers chairman is founder of Murray International Holdings, one of Scotland's largest firms.
Mr Salmond said: "I am delighted to receive a personal endorsement from one of Scotland's most respected business leaders.
"It is all the more significant because David Murray is not a party political person or independence supporter - he is backing a track record of achievement and delivery over these last four years.
"Like David, people all over Scotland will be judging this election on who has the best team and the best programme to take Scotland forward, and I hope that they come to the same positive conclusion."