Although he cautioned that the business could be over-priced, he said: "Primesight is a very interesting proposition and we've expressed our interest. I'm waiting to take a look at the books. We will always look to make new acquisitions where appropriate for the right price."
He is likely to face competition from Clear Channel and JCDecaux. Industry sources said Primesight could fetch up to £60 million.
Primesight, which is a subsidiary of SMG, Virgin Radio's parent company, owns 13,500 six-sheet outdoor panels across the UK and a further 141 large-format backlight panels, mainly in London.
SMG announced last week it was putting Primesight and the cinema advertising company Pearl & Dean up for sale to focus on online. Hawkpoint Partners is handling the sales.
Apfelbaum also revealed that his recent interest in acquiring the train and taxi specialist KBH Transport Media has cooled after failing to agree a deal with the owners.
Titan Outdoor bought Maiden for £10.6 million back in March after saving the company from insolvency.