Mitsui & Co. employees arrested Wednesday on charges of interfering in the bidding process for a government-funded project pressured engineering firm JGC Corp. to cancel a tieup with Marubeni Corp., sources familiar with the case said Friday.

The Mitsui employees' move to thwart the tieup was apparently made to monopolize the bidding process for a government-funded power project on Russian-held Kunashiri Island, in which Marubeni had shown interest.

According to the sources, Masahide Iino, 44, head of a Mitsui industry project team, and other employees of the trading house, demanded that JGC cancel the tieup with Marubeni, a rival trading firm, by threatening to cut JGC out of a project to dismantle decommissioned Russian nuclear submarines.