SMG chief executive Rob Woodward said it has received a number of bids, but refused to comment on prices, or what he believes Virgin Radio is worth.
The timing of the IPO route was hit by last Friday's defection of Virgin Radio chief executive Paul Jackson to GCap Media, which has left SMG with a vacancy that must be filled before it can proceed with any offering.
Virgin Radio chairman Richard Huntingford has said the float could not go ahead until this happens, and analysts now expect it to be delayed from late autumn to next spring.
Price expectations for the business are in the region of £80m-£100m. SMG paid Chris Evans £225m for the station in 2000.
A sale would give SMG more options; however, the drawback is that a new owner would need approval from Virgin brand licence-owner Richard Branson to retain the brand, and he can veto a sale of the radio business to a competitor of the Virgin Group.