SANTANDER, Spain, June 17 (Reuters) - The Chairman of Spanish lender BBVA Carlos Torres on Monday said that one of the reasons behind its takeover bid of Sabadell was the smaller lender's significant market share in lending towards small and mid-sized companies which it vowed to uphold.

Torres said that if the bid succeeded, "we are firmly committed to maintaining Sabadell's SME risk management model, and in fact, except in situations of financial deterioration, we will maintain the working capital lines of all small and medium-sized companies for at least twelve months".

The bank has offered one newly issued BBVA share for every 4.83 in Sabadell, representing a premium of 30% over Sabadell's April 29 closing price of 1.73750 euros, valuing the bank then at 12.28 billion euros. On that day, BBVA shares closed at 10.9 euros each. (Reporting by Jesús Aguado; Editing by Emma Pinedo)