Lord Foster of Thames-side has appointed bankers to examine the possible sale of part or all of his world-leading architectural practice. Foster and Partners, which was broken into six autonomous design groups two years ago is believed to need cash to realise its expansion plans. This includes increasing the number of offices from the current 13 to between 20 and 30. Speculation has put the practice's current value at £300m - £500m GBP. However city financial observers are casting doubt on this price as commercial property is thought to be at the top of its cycle and this is an area which the practice is heavily dependant on making it vulnerable. Foster, who is 71, is believed to have called in specialist corporate finance firm Catalyst Investment to review the funding requirements. In the last accounts filed at Companies House, for the year ended April 2005, the company revealed pre-tax profits of £2.5m on turnover of £44.5m. The London based practice has overseas offices in Beijing, Dubai, Istanbul and Kuala Lumpa which reflects the increasingly international mix of its business, during that year the company generated 12 per cent of its turnover from the US and 9 per cent from China. The bulk of the business, however, was still in the UK, which generated 43 per cent.