Qatar has approached International Airlines Group, the owner of British Airways and Iberia, with an informal offer to become the company's largest shareholder by buying the 12 per cent stake held by Spain's nationalised lender Bankia, the Financial Times reported.

Qatar had approached IAG to ask whether the company would welcome it as a shareholder, the FT said citing two people familiar with the matter.

The financial daily cited one of those people as saying the initial approach was made last year, though it wasn't clear which Qatari entity would buy the Bankia stake.

A third person familiar with the matter told the paper that IAG had informed Bankia of the interest from Qatar about three months ago.

"This is an issue for Bankia and we're not going to comment further," an IAG spokeswoman told Reuters.

Bankia could not be immediately reached for comment by Reuters. It had declined to comment to the FT, saying it would seek the best possible price for its non-core assets.

Earlier this year, Bankia - the biggest failed bank in Spain's history - hired Rothschild to help sell its stakes in companies including power group Iberdrola and insurer Mapfre, as the bank rebuilds its capital. – Reuters