The letter was organised by Keith Cochrane, the chief executive of the engineering firm, Weir Group, who has already warned of “substantial risks” if Scotland votes for independence.
The letter says that “much is at stake”: “Our economic ties inside the United Kingdom are very close and support more than a million Scottish jobs.
“As job creators we have looked carefully at the arguments made by both sides of the debate.
“Our conclusion is that the business case for independence has not been made.”
Among the signatories are HSBC chairman Douglas Flint and Andrew Mackenzie, the chief executive of the mining giant, BHP Billiton, the BBC reports.
But lobby group Business for Scotland said economic “facts and figures” support Scottish independence.
The letter will be published in Wednesday’s Scotsman newspaper.
Scotland will go to the polls in the referendum on 18 September, with voters being asked asked the “Yes/No” question: “Should Scotland be an independent country?”
Other signatories include Audrey Baxter, executive chairman of Baxters Food Group; Simon Thomson, the chief executive of Cairn Energy; and Ian Curle, the chief executive of Edrington, which owns the whisky brands The Macallan and The Famous Grouse.
Its backers say that no political organisations have been involved in putting together the list.
