Spanish construction company Grupo Ferrovial SA launched a hostile bid for British airports operator BAA yesterday, keeping its price at 810 pence per share despite hopes of a higher offer.

BAA, which runs London's Heathrow and Gatwick airports, rejected the £8.75 billion (€12.5 billion) offer, having refused an earlier non-binding bid.

"[ It is] the same price that the board has already emphatically rejected as not beginning to reflect the true value of BAA's unique portfolio of strategic airport assets," it said.

BAA shares have shot up since news of a bid first emerged in early February. Media reports have stated that some key BAA shareholders have demanded the Spanish company offer as much as 900 pence a share.

"This is the beginning of the journey," said a spokeswoman for F&C Asset Management, which owns about 1.75 per cent of BAA. "At the moment [ the bid] is below the share price. So we're looking at it, but it wouldn't be of interest at the moment." Market players said the offer was probably just a first step by Ferrovial in an attempt to mollify BAA's board, win access to its books and decide whether to raise its price in the future.

"This looks like a marker to me," said Paul Mumford, a fund manager at Cavendish Asset Management. "It will flush out any counter-bidders and also force BAA to come out and explain why they're worth more than 810p." Ferrovial, which had until April 24th to announce its firm bid or walk away, had complained that BAA had blocked it from carrying out "due diligence" on the target company's books.

"This offer is a question of process. Ferrovial shows the market clearly that it firmly intends to bid for the company and at the same time force (BAA's) board to talk and be more transparent," a Madrid-based analyst said.