By Daryl Loo

LONDON (Reuters) - A slew of Britain's top property firms are facing a tough outlook in 2010 as their management teams grapple to overcome several high-profile departures, and emerge from one of the industry's worst-ever slumps.

"Most of the companies have lost people. At this stage of the property cycle once you are able to raise the money, people are going to leave," Chris Bamberry, who manages Scottish Widows Investment Partnership's UK Real Estate fund, said.

Capital values in the UK commercial property market have plunged 45 percent on average in the two years to August, and now, as the market hits bottom and opportunities arise, blue-chip real estate firms are facing a mini-exodus of talent.

Senior executives at Land Securities (LAND.L: Quote, Profile, Research), British Land (BLND.L: Quote, Profile, Research), Great Portland Estates (GPOR.L: Quote, Profile, Research) and Helical Bar (HLCL.L: Quote, Profile, Research) have struck out in search of brighter pastures, while Hammerson's (HMSO.L: Quote, Profile, Research) chief executive retired aged 53 in August.

"For companies like Great Portland and British Land it could be a net negative because they've lost some real drivers behind the business," Bamberry told Reuters.

Mike Brown, who quit Helical Bar in May to co-found Max Property (MAXP.L: Quote, Profile, Research) said: "The fact that people are leaving lots of companies simultaneously says less about those companies and more about where we are in the property cycle."

Management teams are already under pressure this earnings season to turn aspirations into reality as the UK property market recovery gathers pace.

The market is looking for detailed and sophisticated plans for these companies grow their portfolios and return to profit, and key focuses will be on merger and acquisition strategy, improving voids and yields, and capital demands.