The national company has bought land to the rear of the A-listed concert hall, and is now searching for architects to compete for the design to transform the landmark venue. Once they are appointed, a major fund-raising campaign will begin.

The theatre, owned by Scottish Opera and run by the Ambassador Theatre Group, will benefit from a refit of its front-of-house facilities for customers, including new lifts, bar areas and toilets, if the plan comes to fruition.

Although the auditorium of the 144-year-old theatre -- which plays host to theatre, comedy, conferences and dance, as well as opera -- is A-listed, other parts of the building are not, and Scottish Opera has long believed that the building needs upgrading for modern audiences.

The venue is the opera company’s key theatre in Glasgow, hosting the majority of its premieres, and although it seats more than 1000, its front-of-house space is limited.

Alex Reedijk, general director of Scottish Opera, organised the purchase of the small piece of land between the theatre and a new office block last year, and said it was a “once-in-a-100-years chance” to gain extra space.

The area is being redeveloped by developer IVG, which had originally planned to build apartments on the land.

“They were planning to build flats on the land, but I saw it as an opportunity to purchase the land, once-in-a-100-years chance, given how long the flats would have been there for, so that we can enhance the Theatre Royal,” Mr Reedijk told The Herald.

“We don’t have enough lifts, toilets, bar space, break-out rooms there, and this is a

perfect opportunity to modernise the theatre. We are now looking for architects to compete for the job, because to raise so much money you need a clear direction, and it is very early days yet.

“Hopefully we will be able to pull it off in time for the Commonwealth Games in 2014, as it would be a great time to get that done.

“The auditorium is protected but not all of the building, which is a mix of grades, but we must wait and see what the architects come up with.”

Mr Reedijk did not reveal how much the company paid for the land, but said it was “not a great deal of money”.

The planning of the redevelopment is now going through the procurement process.

“You can look at the success of the front-of-house developments at Eden Court in Inverness, His Majesty’s in Aberdeen, and the Festival Theatre in Edinburgh, and our plan is all about delivering the same -- a better experience for the audience,” he added.

The Theatre Royal site, on the corner of Hope Street and Cowcaddens Road, has a long history. The first theatre built there, in 1865, was a music hall, but was destroyed by fire two years later. The Royal’s three-feet-thick external walls are thought to date from then.

Twice the theatre was rebuilt, and twice more it was ravaged by fire, in 1879 and 1895, the second time just 48 hours after the insurance policy had lapsed.

In 1957, it was taken over by Scottish Television and turned into TV studios. The One O’Clock Gang variety show was broadcast live from the theatre each day.

In 1972, Scottish Opera bought the theatre and restored it, reopening in 1975. It has been run by London-based promoters ATG since 2005.