spray-paint stencil on traffic bollard by the graffiti artist Banksy, 2002

A mural from the Colony Room, a club frequented by artists such as Francis Bacon, Lucian Freud and Damien Hirst, and a traffic barrier spray-painted by Banksy, will be the star lots of a London urban-art sale in September.

Michael Andrews's 15-foot-long household paint-on-Hessian mural of picnickers had decorated the walls of the drinking club since the 1950s, said Ben Hanly, contemporary-art specialist at the Edinburgh-based auctioneers Lyon & Turnbull.

``He painted it over a weekend in lieu of an unpaid bar bill,'' said Hanly in a telephone interview. ``He found the image in a book on Bonnard, then re-interpreted it.''

The Colony Room was founded in 1948 by Muriel Belcher, who ran the club until her death in 1979. After 60 years in the same Soho building, the lease on the site has expired and the bar is due to close at the end of December, 2008, according to http://www.colonyroom.com.

``This gives us six months to find new premises,'' said the club's current proprietor, Michael Wojas, on the Web site. ``Work on this has already begun.''

The mural, which was removed from the Colony Room last Saturday, will carry an estimate of 20,000 pounds ($39,640) to 30,000 pounds in Lyon & Turnbull's Sept. 27 auction in a church opposite Great Portland Street subway station, near Regent's Park.

Hanly said the lot will also include the original nicotine- stained banquette and lamps that had been in front of the mural. ``It's going to be sold as an installation, rather than just a painting,'' he said. ``It's a piece of London cultural history.''

Andrews Record

Earlier this week, at Christie's International's June 30 contemporary-art auction, Andrews's 1985 painting, ``The Cathedral, The North East Face/Uluru (Ayers Rock),'' sold for a record 937,250 pounds.

Lyon & Turnbull's auction will also include a ``traffic bollard'' with a Banksy spray-paint stencil of a rat paparazzo snapping photographs.

The trademark painting dates from 2002 and is expected to fetch up to 30,000 pounds, said the auction house.

The piece has been entered by Jon Swinstead, the founder of the street-art-prints publisher, http://www.picturesonwalls.com, said Hanly. Swinstead has also entered a number of Banksy prints, including a version of ``Queen Victoria,'' estimated at 5,000 pounds to 7,000 pounds.

Lyon & Turnbull is the second regional auction house to hold an urban-art sale in London.

In June, Dreweatts mounted a 146-lot sale of street art in an industrial space in Shoreditch, east London, which totaled 801,204 pounds with fees.