The much-anticipated initial public offering for Orange, France Télécom's UK-based mobile unit, finally got underway on Tuesday and its shares promptly fell below their issue price amid substantial trading volume.

Orange shares, which were priced at €10 ($9.23) at Tuesday's opening, started trading at €9.9 before quickly falling to €9.7. Heady first-hour trading volume of more than 100 million shares - of a total offering of 633 million - saw scant reward for the marketing efforts of Orange, France Télécom and its bankers.