OSAKA — Osaka Prefectural Police on Thursday arrested two “sokaiya” corporate racketeers on suspicion of accepting 85 million yen in bribes from major machinery maker Kubota Corp. in the form of billboard rental fees, police sources said.

Investigators also searched the Kubota Corp. head office for allegedly handing over 300 million yen to sokaiya over the past 25 years, they said.

The sokaiya arrested Thursday were identified as Isamu Takahashi, 69, the former president of the advertising agency that handles the billboards, and Kiichiro Noro, 52, the current president, police said.

Sokaiya buy shares in firms and extort money from them by threatening to disrupt general shareholders’ meetings, often by making embarrassing revelations.

The Commercial Code bans giving benefits to racketeers.

Police plan to question several senior Kubota officials within the next few days.

The sources said that ties between the sokaiya and the nation’s top maker of farm equipment and cast iron pipes go back nearly 25 years, with Kubota paying out at least 300 million yen.

The two alleged racketeers agreed not to disrupt Kubota’s shareholders’ meetings in return for between 15 million yen and 18 million yen annually in “billboard rental fees,” the sources said.

The pair are allegedly so-called friendly sokaiya — racketeers who stay on the sidelines of the meetings and keep “hostile” racketeers in check. Together they held more than 1,000 Kubota shares. The cost of renting the billboards, on atop a building in the city of Toyonaka, Osaka Prefecture, and another in Nagoya, was above the market price for similar ad space, some industry sources said.

Kubota announced in November 1997 that it would sever all ties with sokaiya.

The Commercial Code was tightened against sokaiya one month later, but police sources alleged the company kept making unlawful payments to them.

Three of its senior sales officials were arrested in February last year for playing a role in a price-fixing cartel for pipes. Their guilty verdicts took effect last March.