Propex, the online UK commercial property information provider, is poised to be bought for £12m by US company CoStar

The shareholders of Propex, who are many of the best known investors and agents, have agreed to sell the company, and the deal is expected to be announced next Wednesday by NASDAQ-listed CoStar.

The Mayfair-based Propex team is led by managing director Paul Marples and commercial director Colin Barber. Formed in 1999 it struggled for years to attract business but has taken off in the last couple of years. It now has three services, Propex Professional, which is an online trading platform that receives 10,000 introductions a month, Shopproperty, a listing site of all available shop units to rent across the UK, and Screenedata, a database of available business space) in London and the south east.

In the year to 30 April 2006 Propex generated turnover of £1.7m but recorded a loss of £13,896. Propex Professional was the biggest contributor, making turnover of £1m, up from £710,000 in 2005.

CoStar was founded in 1987 and came to the attention of the UK market four years ago when it bought Property Intelligence, which operates Focus Information, for $16.4m (£8.2m). It floated on NASDAQ in 1998 and has a market capitalisation of $882m (£440m).