Domino's Pizza is to return £19m cash that is surplus to requirement back to shareholders though a tender offer for 6m shares at 317p.Four directors will take part in the tender in respect of their own shareholdings. They include chief executive Stephen Hemsley; Colin Halpern; Christopher Moore; and Nigel Wray. Brokers Numis and Altium are handling the tender offer.Since 2004, Domino's has bought back 23m shares and returned approximately £31.7m of cash. Going forward, it intends to purchase approximately 2% to 3% of the existing issued share capital each year, it said today.Trading has continued strongly since its last update in September and the board is confident of the company fully meeting the market's current expectations for the full year, the pizza group added.At the end of last week, Domino's was valued at £330m.