It came after a formal approach was made by a consortium of investors, including Glasgow City Council's pension fund, the Strathclyde Pension Fund, to the Spanish owners of the airport.
Consortium representatives spelt out in a letter to Heathrow Airport Holdings (HAH) their interest in buying the airport and have requested guidance on how best to initiate dialogue and a bid of around £500 million.
No offer is likely to be made until the bidders are given an opportunity to scrutinise the airport's accounts.
The move was made just hours after the Evening Times yesterday revealed an attempt to purchase the airport was to be made by major investors, including the Strathclyde Pension Fund, which is used by the city council and Renfrewshire Council.
It has assets of £13.5 billion and will be an important partner in the consortium, which is led by the Swiss-based Partners Group, a global private investment firm which masterminds more than 30 bn Euros of investments.
Asked when a formal bid will be lodged, a spokesman for the Partners Group, said: "We can confirm we are in the process but can't give you any information regarding the timing."
There is speculation that a cash offer of around £480m will be lodged but, speaking from the group's Swiss HQ in Zug, the spokesman said: "We can't comment on the actual price."
No cash offer is likely to be made until the bidders are given an opportunity to scrutinise the airport's financial records. Only when due diligence is completed is a formal bid expected to be tabled.
And the Evening Times can reveal that the investors have been considering buying the hub from HAH for at least two years, following the Competition Commission's ruling that it must sell off either Glasgow Airport or its sister operation in Edinburgh.
HAH eventually opted in 2012 to sell Edinburgh - the most successful of the two - for £800m.
The Partners Group spokesman said: "We have been looking at it for quite some time."
Gordon Matheson, leader of Glasgow City Council, said: "Glasgow Airport has huge strategic importance for our city and also the wider regional and national economies.
"It is Scotland's principal long-haul gateway and has an extensive schedule of European and domestic flights, including vital routes to the Scottish islands."
Councillor Matheson, who backs the takeover attempt, said: "A bid that brings together a strong local and regional interest, strategic management skills and long-term capital, offers the best possible opportunity to meet the needs of local business and leisure travellers."
Backing has also come from his opposite number at Renfrewshire Council.
Council leader Mark Macmillan said: "Glasgow Airport is vital not only as a transport hub but also as a focal point for employment, investment and economic growth in Renfrewshire and the west of Scotland.
"It is very encouraging to see this level of interest and confidence in the airport's future prospects from such a wide range of leading private and public institutions.
"I believe the combination of locally-based involvement backed by international investment and financial expertise would be ideally placed to meet and benefit from our region's economic interests and maximise the growth potential for investors."
Glasgow Chamber of Commerce represents around 2000 firms in the area.
Chief executive Stuart Patrick insists he will welcome investment which grows the airport business.
He said: "We consider Glasgow Airport to be the most important transport asset the city has for business to access markets abroad.
"The management team has been doing an excellent job in growing the business over the last three years and we support any owners who can provide investment funding that will maintain that growth.
"Clearly the two councils understand the importance of the airport but, naturally, the consortium will be making its decision on investment returns.
"We know there are very attractive returns to be made from an investment in the airport as we believe in the potential of the west of Scotland economy."
The move has also got the thumbs up from the trade union movement, including Unite - Britain's biggest union - and Alex McLuckie, senior organiser of the GMB, who led the equal pay fight for thousands of women council workers across Glasgow.
Mr McLuckie said: "It is for the Strathclyde Pension Fund managers to get the best possible return on their investments.
"We would not be opposed to such am investment so long as it met our strict ethical standards."