SCM offered to buy back two-thirds of its stock.

Under the offer, SCM will exchange cash and securities valued at $74 per share for 8.2 million shares of its own stock. SCM said it wanted to protect shareholders in case neither of two competing bids for SCM succeeds. Hanson Trust PLC, a British conglomerate, launched a hostile bid for SCM in August. SCM has agreed to a leveraged buy-out by Merrill Lynch and members of SCM’s senior management.