Trafalgar is preparing a hostile bid for Minebea.

The Los Angeles-based investment firm, headed by financier Charles W. Knapp, said it will make an unfriendly offer for the Japanese ball bearing manufacturer because Minebea’s board has apparently rejected a previous $1.43-billion buy-out plan. “We now intend to take an offer directly to (Minebea’s) shareholders,” said a statement from Trafalgar and its British partner, Glen International. The American and British investors also announced that they will “legally challenge” recent anti-takeover moves enacted by Minebea, including a recent issue of convertible debentures and the proposed acquisition of a Japanese apparel manufacturer.