Sky News has reported that the announcement of the takeover by Inflexion Private Equity could be made early this week.
If successful, the £70 million would be considerably more than that which founder and chairman Andrew Dunn expected when he appointed Cavendish Corporate Finance to consider options for expanding the business.
The news comes after Inflexion recently raised a £1 billion fund to invest after it exited a number of earlier deals.
Scott Dunn was set up in 1986 and currently makes annual profits of about £6 million.
An Inflexion spokesman refused to comment to the Sky News report.
