LONDON (Reuters) - In a fight to win back fans from the "gray zone" of online song-swapping services, the music industry is borrowing a trick from its nemeses: free music downloads.

For one week beginning Thursday, music fans in Europe will be able to download, stream or burn onto their hard drives a selection of tracks from 6,000 artists including ColdPlay, Dido and Elvis Presley.

It is part of a marketing ploy called "Digital Download Day" devised by British firm OD2, a technology company specializing in digital music distribution and co-founded by recording artist Peter Gabriel.

Backed by record labels and music retailers, a host of subscription download services have been hatched over the past year to tap into the consumer craze of downloading music.

But the pay-for services are still no match for free download services such as Kazaa and Morpheus MusicCity, which claim tens of millions of users. The major labels blame the availability of free music downloads for a drop in CD sales.

The free download, or peer-to-peer services, brand themselves as "file sharing" Web sites and do not actively condone downloading copyrighted files such as music or video.

But the music industry brands them as pirates, and has launched a number of high-profile lawsuits against them, recently claiming the scalp of now-defunct peer-to-peer pioneer Napster. "We're now facing a marketing challenge," said Ed Averdieck, marketing director for OD2. "We need to show the public that instead of downloading from ... one of the file-swapping services, you can download from the legal sites."

OD2 builds subscription music download services for retailers and Web firms. Its clients include Internet service providers Tiscali, Wanadoo and Microsoft Corp.'s MSN web portal, plus retailer HMV Group.

TOUGH TALK GOES UNHEEDED

The Digital Download Day initiative is a tactical change in strategy for the industry. Averdieck, for one, believes the tough-talking approach is not nearly as effective as giving consumers the option to try the services for free.

"Paying for music has to be a better option ... any initiative that helps create that atmosphere is to be welcomed," said Andrew Yeates, director general of the British Phonographic Industry, in a statement.

Lately, the labels have gone on the offensive.

Last week, industry trade group the Recording Industry Association of America (RIAA) said it will air a series of television ads featuring Britney Spears and Madonna that likens the act of downloading music to stealing.

Record executives have used a host of public gatherings to chastise what it calls the rampant rise of consumer piracy.

The efforts have done little to quell the activity though. Various industry research reports have shown that the number of songs downloaded each month has matched, or even surpassed, the number of songs purchased.

OD2 has secured the digital streaming rights to 100,000 songs from a variety of major and independent music labels.

The company has enlisted some 50 recording labels, including EMI Group and Bertelsmann's BMG, plus its retail and Internet partners to allow consumers to sample the subscription services as part of the marketing initiative.

The program will be open only to European Web users.

Consumers who register on one of the six participating sites, including www.msn.co.uk, www.tiscali.co.uk and www.hmv.co.uk, will get $7.90 worth of digital music to sample or burn.