Nissin Food Products Co. said it adopted a plan Monday to discourage hostile takeover attempts, a move that could be opposed by its biggest shareholder, U.S. investment fund Steel Partners.

The scheme, endorsed by Nissin's board of directors, would apply to any company planning to acquire a stake of 20 percent or more. The prospective buyer would have to submit a report in advance on the purpose of the stake and other related information.

If the bid is deemed unfriendly, Nissin would issue equity warrants to existing shareholders.

The company said it will seek approval of the scheme at its general shareholders' meeting June 28. Nissan said it will adhere to shareholders' wishes on the matter.

An equity warrant entitles the holder to buy a specific number of shares at a specific price for a set period of time.

A PR official at Steel Partners said the fund will decide whether to oppose the scheme after an in-depth study.

But Steel Partners, which owns around 12.6 percent of outstanding Nissin shares, may voice opposition as the fund, the biggest shareholder in both beer brewer Sapporo Holdings Ltd. and wig maker Aderans Co., has proposed that those firms cancel similar antitakeover measures.

Last November, Nissin made Myojo Foods Co. a consolidated subsidiary through a friendly tender offer carried out to counter a hostile buyout attempt by Steel Partners.