Part of one of Brisbane's main inner-city streets – William Street – will be closed for six years and 50 bus routes will be changed before Christmas to allow work on the new Queens Wharf Casino to begin.

It is the beginning of almost $10 million of major inner-city roadwork changes needed to begin construction of the new multi-billion dollar Queens Wharf casino and entertainment resort between George and William streets.

William Street – used by 8000 vehicles each day - will be closed between Elizabeth Street and Margaret Street before Christmas and stay closed for six years.

That will allow the demolition of the Executive Building – between George and William streets - and of the Neville Bonner Building on William Street in early January 2017 and then major construction.