By Jennifer Hill

LONDON (Reuters) - Property auctions are growing in popularity, but savvy buyers do their homework first.

A decade ago, fewer than 15,000 properties changed hands at auction. That figure has risen to more than 35,000 per year, according to the Essential Information Group (EIG).

Whether you're thinking of attending your first auction or you're an old hand, preparation is the key. First things first: research the market.

EIG (www.eigroup.co.uk/ 0870 1123040) is a good port of call. It has expanded to cover the whole of the UK since it was founded in 1990 to provide the property industry with information on London property auctions, and now provides details of every British property that goes under the hammer.

Its database includes more than 400,000 properties worth more than 5.6 billion pounds in all.

Check out local estate agents, too, to see what properties are priced at.

EIG, a subscription-based service, also gives details of homes about to go to auction. Listings include full catalogue entries, guide prices and auction dates.

You could also join the mailing list of auctioneers in the area in which you are looking to buy.