Scottish Media Group will sell its current television premises for an estimated 5 million, and the Renfield Street building will be converted for residential use.
In a notice sent to staff, Donald Emslie, the chief executive of SMG Television, which also owns Grampian Television, said he hoped the move to Pacific Quay would be completed by the summer of 2006.
The company had been considering relocation to two possible Glasgow sites - Central Quay in the north side of the river, or Pacific Quay in the south, adjacent to the new 130 million BBC Scotland headquarters.
A favourable deal with the developers of Pacific Quay and a river-frontage site swung the decision in favour of the south.
"Since October we have been working with the developer on a ‘back-to-back’ deal where they would purchase our Cowcaddens site and provide for us, under lease, a customised building at Pacific Quay," said Mr Emslie.
"Progress is being made, the outline building design is at an advanced stage and initial informal meetings have taken place with the council planning department."
He added: "We still have a long way to go and I am still of the opinion that if we can pull this off it will be a fantastic achievement.
"In overall terms, negotiations are now at an advanced stage. If things go well, we would hope to reach agreement with the developer on the commercial aspects of the deal by the end of March."
The bespoke building will be developed for SMG by Pacific Quay Developments, a combined venture with the Duke of Westminister’s property firm, Grosvenor, Miller and CTP.
Architect and design firm Parr Partnership, which has worked on No 1 and No 2 Pacific Quay, will design the building.
The developers hope the arrival of the BBC and SMG will prompt more smaller production firms, and other television and media companies, to move to the area.
In June last year, SMG relocated Grampian TV to a state-of-the-art facility on the outskirts of Aberdeen after selling its Queen’s Cross studios for redevelopment. Mr Emslie said the firm had seen great benefits from Grampian’s switch to more modern premises, including a 1000-sq ft automated studio.
When Scottish TV finally moves from Cowcaddens in 2006, it will end a golden era of broadcasting from the top of Glasgow’s Renfield Street.
Founded by a Canadian newspaper magnate, Roy Thomson, Scottish Television began broadcasting from Cowcaddens in 1957.
The first programme ever transmitted was This Is Scotland, a live showcase of international and local talent presented by James Robertson Justice and starring Deborah Kerr, David Niven, Jack Buchanan, Alistair Sim and Moira Shearer.
When STV went on air, only 187,000 television sets throughout Scotland were able to receive the station’s output, but the audience for the opening programme was 750,000 viewers.
Over the years, the station has used the Cowcaddens studios to full advantage, with some of their original programmes, including the One O’Clock Gang, gaining legendary appeal.
The five-days-a-week music and comedy show, starring Larry Marshall, Jimmy Nairn, Charlie Sim, Dorothy Paul and Moira Briody, ran for 1,760 programmes, the last transmitted in 1966.
Many of Scotland’s top acting and comedy stars began their careers at Cowcaddens.
The cult TV comedy series Francie And Josie, starring Jack Milroy and Rikki Fulton, was another classic.
Scotsport, formerly presented by Arthur Montford and Jim White, is another long-running programme. Still with the same name, it remains the longest-lasting of its kind on UK television, and is currently presented by Jim Delahunt.
Glen Michael’s Cartoon Cavalcade, complete with Rusty the dog and Paladin the grumbling lantern, was essential viewing for all Scottish children during the 1970s, while Fun House topped the polls in the 1990s.
Crime series Taggart, broadcast in 1983 and still in production, has provided the stepping stone for many of Scotland’s acting stars. Ewan McGregor, Joe McFadden, Jason Connery, Billy Boyd, John Hannah and Robert Carlyle were all graduates of the Maryhill drama.
After 18 years, Taggart entered the record books as the longest-running police drama on television.
A spokesman for SMG confirmed that Pacific Quay was the preferred option for a new site but declined to comment further.
Growing audience-appeal for small-screen company
1957: Scottish Television begins broadcasting at its new building in Cowcaddens.
1959: First Scottish coverage of the General Election.
1962: The Beatles make their first television appearance on STV.
1968: Afternoon broadcasts introduced. STV’s licence requirement increases by three and a half hours per week.
1969: A serious fire puts the main Cowcaddens studio, Studio A, out of action.
1972: Building work starts on new studios.
1974: The original home of STV, the Theatre Royal, is sold to Scottish Opera for conversion as Scotland’s first opera house.
1976: Transmission of European Cup Final from Hampden Park, the biggest sporting outside-broadcast ever undertaken at that time by an ITV company.
1980: Programme on the life of the convicted murderer James Boyle, titled A Sense of Freedom, goes into production.
1983: Transmission of three-part drama series, Killer, the first appearance of Glasgow detective Jim Taggart, played by Mark McManus.
1983: Transmission of first episode of Take The High Road. The series later changes its title to High Road.
1984: Transmission of Scotland’s Story, a 24-part history of the nation.
1985: Launch of new identity as Scottish Television and change of "STV" logo to the "thistle" design.
1988: Transmission of The Steamie, a version of Tony Roper’s stage play about life in a Glasgow wash-house in the 1950s, starring Dorothy Paul and Eileen McCallum.
1988: An edition of Taggart, entitled Violent Delights, is watched by more than 18million viewers, the biggest-ever audience for the series.
1993: Transmission of the first episode of Doctor Finlay. The series starred David Rintoul, Ian Bannen and Annette Crosbie.
1995: Pilot episode of McCallum, starring John Hannah, is transmitted on the ITV network to an audience in excess of ten million.
1995: Gus Macdonald, now Lord Macdonald, is appointed chairman of Scottish Television. Andrew Flanagan is appointed chief executive.
1997: The company changes its name to Scottish Media Group, but Scottish and Grampian Television brands remain.