A landowner south of the Yarra River with an existing planning permit has cashed in on a Southbank development site for $27 million after the state government's surprise introduction of new rules curbing skyscrapers ahead of a year-long central city planning review.

The off-market deal was negotiated by Lemon Baxter's Jonathan Walls and Richard Hutton.

The two-level office and showroom which returns a holding income of $380,000 per annum has approvals for a 60-level structure with 431 apartments.

It sits on a 1265-square-metre site at 256-260 City Road that was one of the few remaining substantial development blocks on a strip dominated by developers Central Equity and the Salvo Group.

Another similar-sized landholding nearby across three adjoining lots between 268-274 City Road sold to Central Equity in May for $21 million without a permit in a campaign managed by Conquest Estate Agency.

Central Equity has since applied to Planning Minister Richard Wynne for a 60-level structure on the site which currently includes a collection of warehouses, one of which is leased to the Fabrique nightclub.

Mr Walls said the purchaser, an Asian-backed development group, had no immediate plans to develop the Hayball-designed apartments.

"The price reflects the value of a permit especially in the current market where changes and uncertainty have led to a reluctance from developers to take on the planning risk, especially when it comes to high rise developments," Mr Walls said.

City Road is fast becoming Melbourne's most active development strip.

Central Equity is also planning a 67-level structure with 782 flats on sites between 71-87 City Road, opposite the Eureka Tower (which contains 556 apartments in 92 levels).

And LK Property Group will develop a 37-level, 246-unit complex on a 972-square-metre site further down at 57-61 City Road.

On the same side of the river, Savills Australia recently re-listed one of Melbourne's largest development sites, a huge 9776-square-metre block at 60-82 Johnson Street which in May received state government approval for more than 1300 apartments across four towers.

The site is owned by prominent developer Vicland Corporation, controlled by Bill McNee, which acquired it for $10.1 million in September 2013 from the family that founded corporate hire company Kennards.

Industry sources suggest it is likely to fetch more than $70 million with the market placing a premium on permitted sites.

Vicland had signed a contract of sale for the site soon after purchasing it with Hong Kong-listed, Guangzhou-based R&F Properties subject to receiving development approval but the deal, believed to be above $50 million, fell over after the site failed to get a permit within the required window.

R&F Properties has since become active in the Brisbane market.