He told the BBC Politics Show of his intentions, which have raised fears of job losses in the UK financial sector.
More than 1,500 banking jobs could be lost as a result of the UK government's plan to sell off the insurance operations of RBS, the Scottish National Party (SNP) has warned.
The SNP, which holds power in the Scottish Parliament, said that it feared for those working in RBS banking jobs in Glasgow should the sale go through.
Finance secretary John Swinney added he was worried about the implications of a forced sale.
"They [the insurance divisions] must not be disposed of in a way that would be damaging to jobs, and therefore the Scottish government will be seeking specific assurances regarding the future of these vital posts," he said.
By Gary Cooper