LONDON, March 5 (Reuters) - U.S. pop star Michael Jackson is
expected to announce a series of comeback concerts on Thursday.

The 50-year-old, still viewed as "The King of Pop" by his
fans, has lived the life of a virtual recluse since his
acquittal of child abuse charges at a 2005 trial.

Jackson's last album of new material was "Invincible",
released in 2001, and his position as one of pop music's biggest
acts has been increasingly overshadowed by bizarre behaviour, a
changing appearance and questions over his health.

Organisers have not disclosed details of the comeback, but
Billboard magazine reported that Jackson's Las Vegas-style
"residency" at London's 20,000-capacity O2 arena would kick off
in July.

The first 10 dates have been booked, and the length of the
run would depend on demand for tickets, Billboard added.

Jackson is expected to be at a press conference later on
Thursday to confirm the dates.

Even before a single concert has been confirmed, there is
widespread scepticism that Jackson is capable of playing a
potentially lengthy series of gigs.

British bookmaker William Hill has offered odds that Jackson
would not turn up for a run of concerts.

Jackson is one of the biggest musical acts of all time, with
an estimated 750 million albums sold. "Thriller", released in
1982, is the best selling album ever.

If he can pull it off, the string of concerts at a single
venue would be both lucrative and less demanding than a
full-fledged tour.
But if the comeback fails to materialise, or is regarded as
a flop, Jackson would find it harder than ever to resurrect a
career that has lain lifeless for so long.

Jackson performed in London at the World Music Awards in
2006, but the much-hyped return was described by critics as a
shambles after he sang, in a broken voice, just a few lines of
his charity single "We Are The World".

Fellow performer Prince gave his profile a major boost with
a successful 21-night stay at the O2 in 2007 which amassed a
reported $22 million, and Britney Spears is due top appear there
in June.

Jackson began his musical career with his siblings in the
Motown group the Jackson 5 and went on release a string of hit
solo albums.
(Reporting by Mike Collett-White, editing by Paul Casciato)
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