LONDON (Reuters) - A government-backed savings provider is launching a search to reunite customers with more than 400 million pounds of their money.

National Savings & Investments (NS&I) is, for the first time, advertising in the press, on the Internet and over the radio to trace savers.

Some 435 million pounds is lying in accounts that have lain dormant for at least 15 years.

The main dormant accounts are Post Office savings accounts, ordinary accounts and investment accounts.

The most common reasons for people losing track of their accounts is moving home without updating their address details and forgetting about accounts opened for them as a child.

Since NS&I introduced its tracing service in November 2001, 43,000 people have been reunited with 42 million pounds.

Peter Cornish, customer director at NS&I, said: "We want to help re-unite as many people as possible with savings they have forgotten they had invested with NS&I, or as we were formerly known, National Savings.

"We have launched an advertising campaign to jog as many memories as possible and the service is completely free of charge."

To use the tracing service, log on to www.nsandi.com or call 0845 9645000. There is no time limit on making a claim.