Quartermile, the development group under new ownership, has announced the appointment of international real estate firm CBRE Hotels to market the sale of the flagship hotel on its unfinished central Edinburgh site.

The Residence Inn by Marriott opened in autumn 2011 and won the 'new business of the year' award from Edinburgh Chamber of Commerce in 2013.

Designed by world-renowned architects Foster & Partners, the 107-bed 'extended stay' hotel is the first in the UK for the Residence Inn chain, which was acquired by Marriott in 1987 and now extends to 600 hotels in the US, Canada and Mexico.

Paul Curran, managing director of Quartermile, said: "This is an excellent opportunity to purchase a highly successful hotel operation in an unrivalled and continually growing location. We are confident that the strength of the Marriott brand combined with CBRE's expertise in this area will lead to a high level of interest."

The high-end hotel brand offers longer-stay accommodation, with studios and one-bedroom suites, the rooms are all equipped with a kitchen, and facilities include a fitness centre.

Robert Seabrook, executive director at CBRE Hotels, said: "We are delighted to be involved in the sale of this exceptional management-encumbered extended stay hotel. The Quartermile development is reaching a stage of critical mass, the Residence Inn brand is gaining traction in the UK and Europe, and the UK and Edinburgh hotel markets are accelerating. The confluence of these drivers, coupled with the straightforward operating model and strong asset fundamentals should make this property highly appealing to a broad array of investor groups."

Marriott competes in the US with other extended stay brands run by Intercontinental, Hyatt and Hilton. In the UK Marriott has 63 hotels including six in Scotland, ranging from the Courtyard Aberdeen Airport at £55 a night to Edinburgh's Glasshouse at £110 and the Residence Inn at £151.

Quartermile meanwhile is regaining momentum after being mired in the property slump since early in its development.

The 19-acre site of the city's Victorian Royal Infirmary was acquired by Gladedale Capital in 2005 from original developers Bank of Scotland, Taylor Woodrow and Kilmartin Property Group, which went into receivership in 2010 owing Lloyds Banking Group some £200m.

Gladedale sold in September 2013 to Moorfield Group . The site was originally predicted to have an end value of up to £500m once it was developed into a "vibrant cosmopolitan new quarter" supporting 5000 jobs.

Office occupiers include Investec, Skyscanner, Morton Fraser and Maclay Murray Spens while retail units have been taken by the likes of Sainsbury's, Starbucks, Peter's Yard and most recently Italian bar Enzo.. Apartments on the site range from Apartments at the site range in price from £250,000 for a one-bedroom flat to £1.8 million for a penthouse with a view.

Gladedale had put expected completion of the site back to 2016 while Moorfield has now said it will be 2018.

The firm has abandoned plans to convert two B-listed medical pavilions at the centre of the site into a boutique hotel, and intends to turn them into luxury apartments instead.