Refco Group, the futures broker preparing a stock market flotation, could face action from the Securities and Exchange Commission, the US regulator, over allegations of short sales of stock of Sedona Corporation, a US technology group, and other transactions.

In a filing on Monday, Refco said its securities subsidiary had received a Wells notice from the SEC. Such notices indicate that the regulator has found potential infringements to US securities laws, and could push for enforcement action.