Spain's market supervisor authorises bank BBVA's higher offer for Sabadell

MADRID (Reuters) -Spain's stock market supervisor said on Thursday it had authorised banking group BBVA's improved 17 billion euro ($20 billion) bid for smaller rival Sabadell, which was announced on Monday.

Shareholders will now have until October 10 to tender their shares, compared with October 7 for the previous offer, with results expected to be published seven days after the end of the acceptance period.

Sabadell has up to five days from the authorisation to issue an opinion on the improved new bid, though Chief Executive Cesar Gonzalez Bueno has already said the board would "probably" not recommend the new price he still considered insufficient.

Under the new terms, BBVA is offering one of its own shares for every 4.8376 Sabadell shares.

This represented an increase of 10% to 3.39 euros per share, or about 17 billion euros, from the previous offer of 3.084 euros per share, or 15.5 billion euros, based on closing prices on September 19 and the previous exchange ratio.

The bid represented a premium of 1.6% to Friday's market close. As shares in Sabadell have underperformed BBVA's since the new offer was announced, the premium has risen to 2.89% as of Wednesday's close.

($1 = 0.8482 euros)

(Reporting by Jesús Aguado. Editing by Inti Landauro and Mark Potter)