Sony vice chairman and the chief of its entertainment operations Sir Howard Stringer today warned of the growing threat of online movie piracy from broadband-connected homes, as the entertainment giant announced plans for its own legal online music service.

Speaking to Sony dealers in Paris, Sir Howard said that more than 50 new movies had been stolen and made available on the internet before their official release dates, in the first six months of this year alone.

He also said that around 500,000 illegal copies of recently released films were being traded on the internet everyday, a figure that is expected to increase with the growing penetration of broadband-equipped homes.

The Sony entertainment chief also pointed to the $7bn that the music industry is estimated to have lost to piracy over the last two years.

In an effort to thwart internet pirates Sony has already launched a legal movie download service. Alongside Metro-Goldwyn-Mayer, Paramount Pictures, Warner Bros., Sony's Sony Pictures and Universal Pictures, Sony is a partner in Movielink, the US-only online film service.

Yesterday Movielink boss Jim Ramo said the service "continued to gain momentum," as it unveiled new software that made the service easier to use, quicker to download and harder to copy.

In a bid to beat the billion dollar pirates Sony announced that it was following computer giants Apple and Microsoft in launching a new legal music download service.

Sony's Net Music Download service, as it will be called, will launch in Japan early next year before rolling out in the US and Europe in the spring.

The new service will combine "efforts of our music, electronics and picture companies," Sony's group president and chief operating officer Kunitake Ando said.

Net Music Download is the latest attempt by record companies to try and convince downloaders to switch to legitimate services and away from so-called illegal sites such as Kazaa and Morpheus.