The Livedoor Co. group used investment unions in corporate takeovers done through stock swaps, having them transfer the stock-sale gains made in the deals to it in the form of dividends, and cleared the actions with a consultant and a lawyer beforehand, prosecution and other sources said Thursday.

The sources said such gains were treated in Livedoor's financial statements as extraordinary gains, instead of capital surpluses, which some accountants suggest is the proper way to deal with profits made through the selloff of a company's own shares.

The Livedoor group carried out 18 corporate takeovers through stock swaps since 2001, the sources said.