Ferrovial, the Spanish owner of the UK's major airports including Glasgow, Edinburgh and Aberdeen, has finally been given the green light for a refinancing which ought to pave the way for reinvestment.

Institutional investors holding the bonds used by Ferrovial to help buy BAA at the height of the credit boom in 2006 for £16bn have signalled support for a $9.5bn (£4.8bn) bond exchange, which also sees the three Scottish terminals and Southampton - BAA's "unregulated" airports - hived off into a separate entity.

The investors will accept new securities paying higher interest and ranking as senior secured debt, in place of current unsecured bonds, with the same maturities. They will be backed by BAA's Heathrow, Gatwick and Stansted airport assets and the Heathrow Express train link.

The refinancing had been paralysed by the markets, but in recent weeks gained traction as Ferrovial won backing from banks for a £7.65bn loan and BAA started talks with debt investors.

The news yesterday drove down the cost of insuring BAA's debt against default in the credit derivatives market, and the Spanish group's shares jumped by 7%.

"The refinancing deal provides us with a sense of security," said a Madrid-based trader.

BAA said: "Bondholders who decide to participate in the refinancing will benefit from a comprehensive security package, operational covenants, financial protections and enhanced transparency in terms of investor disclosure and forecasting."

It said a special committee of bondholders at the Association of British Insurers had informed the company the proposed refinancing was acceptable. These holders will ask other members of the ABI to vote in favour.

In addition, the new debt is expected to be rated A- by both Standard & Poor's and Fitch Ratings, the company said, an improvement on current ratings.

Bondholder meetings are scheduled for early next month.