Olympic stadium in the dark

London - Work to dismantle the first of the 14 iconic triangular floodlights on top of London's Olympic Stadium began on Wednesday as its transformation into the home of Premier League club West Ham United continued.

The 500 tonne lighting towers, a defining symbol of the 2012 Games and an addition to the east London landscape, will be taken down and replaced with similar-looking lights underneath a new 45 000 square metres roof.

West Ham were controversially accepted as the preferred bidder to become long-term tenants at the stadium last December after a lengthy saga over its future use, and are planning to begin the 2016-17 season at their new home.

"This marks a key milestone in the stunning, £200 million transformation of the Olympic Stadium - one that will culminate in an iconic new home for our club, West Ham's vice-chairman Karren Brady told the club's website on Wednesday.

"My team and I fought exceptionally hard on behalf of our supporters to ensure these modifications, which we knew were of paramount importance to our supporters, took effect."

The roof is being re-designed to cover all the seats, some of which will be retractable so that the running track can remain in place.

The capacity of the stadium, which cost £430 million to build, will reduce from 80 000 to around 55 000 once the expensive re-modelling, some of which is being met by the British taxpayer, is complete.

"It was vital for us that this stadium offers an incredible viewing experience for West Ham fans and I think that will become ever clearer as the conversion progresses," Brady said.

"We're wholly committed to delivering a state-of-the-art home for West Ham United by 2016 that will honour the Olympic legacy pledge.

"Today represents another significant step toward that hugely exciting goal."

Before West Ham move in, the stadium will host some matches in the 2015 Rugby World Cup.

The decision to hand West Ham a 99-year lease was met with criticism with former sports minister Richard Caborn saying the deal between the club and the London Legacy Development Corporation, the public body responsible for the stadium, "the biggest mistake in the Olympics."

"West Ham are basically getting a stadium costing more than £600 million for just £15 million and a small amount in annual rent," he told British media last year.

Local English third-tier club Leyton Orient also mounted a legal challenge to the West Ham move, saying it would threaten their existence.