Scottish Opera has announced the names of five shortlisted architectural practices to design an extension to the Theatre Royal Glasgow in Scotland.

The practices include Caruso St John and Nord Architecture, Terry Pawson Architects, Tim Ronalds Architects and Scottish based Page / Park.

The multimillion-pound project will involve work on public space in front of the theatre.

The final winner is expected to be announced in mid-January 2010.

Scottish Opera is the national opera company of Scotland.