LONDON (AFP) - British singer Sarah Brightman said Wednesday she was suspending plans to launch into space to perform on the International Space Station (ISS) due to "family reasons".

The Phantom Of The Opera singer had paid US$52 million (S$69 million) to fly to the ISS, and hoped to become the first soprano to sing on board.

A statement on Brightman's website said that she was postponing cosmonaut training and her plans to launch on the Soyuz TMA-18M spaceflight mission, scheduled for September.

"Ms Brightman said that for personal family reasons her intentions have had to change and she is postponing her cosmonaut training and flight plans at this time," the statement read.

Brightman, 54, was learning Russian and survival skills as part of her training regime with cosmonauts and astronauts from Nasa, the Russian space agency and the Japanese space agency.

She had been working with her ex-husband, composer Andrew Lloyd Webber, to come up with something "beautiful" to sing while in space.

The singer-actress has spoken of a lifelong dream to fly to space, and described watching the moon landings in 1969 as "a pivotal moment" in her life.

"We've seen first-hand her dedication to every aspect of her spaceflight training and to date, has passed all of her training and medical tests," said Eric Anderson, co-founder and chairman of Space Adventures in a statement.

"We applaud her determination and we'll continue to support her as she pursues a future spaceflight opportunity."

Brightman hoped to become the first space tourist since 2009, and was training alongside a Japanese businessman ready to take her place if she dropped out.

A 30-million record selling artist, Brightman had a British top 10 hit with I Lost My Heart To A Starship Trooper in 1978 before her stage career took off with Cats in London's West End.