An investigation into alleged payoffs by Seibu Railway Co. to "sokaiya" corporate extortionists has revealed that three executives of the firm sold two land plots in Kanagawa Prefecture shortly after turning down a real estate company's purchase offer, Tokyo police sources said Thursday.

The sources said that the three executives arrested Monday -- Seiichi Ikura, 65, senior managing director; Norihiro Kanno, 59, head of public relations and a board member; and Masaru Kojima, 55, head of the real estate department and also a board member -- decided to sell the land below market price to avoid trouble with racketeers, even though the plots were not for sale.

The sources said the bargain deals were sealed in January and May 2001, shortly after Seibu turned down the real estate agent's offer to purchase the two lots -- one in Yokosuka and the other in Kamakura. The real estate firm had approached Seibu around fall 2000.

Soon after Seibu turned down the offer, another real estate broker seeking to buy the same lots allegedly conspired to bring in the well-known sokaiya Ryuga Haga, 74, who is also under arrest, for negotiations with Seibu, the police sources said.

The sources said the real estate company contacted Haga through another real estate company based in Yokohama. None of the firms was identified.