UBS agreed to buy its embattled rivalCredit Suissefor 3 billion Swiss francs ($3.2 billion) Sunday, about less than half of Friday's closing price of $8.4 billion for Credit Suisse.with Swiss regulators playing a key part in the deal as governments looked to stem a contagion threatening the global banking system.In order to preserve Credit Suisse and execute a successful takeover, Switzerland changed the law to allow both parties to bypass shareholder approval.Thus, as long as the board approved the sale, shareholders cannot question the sale price or the terms of the sale, resulting in shareholders who attempted to hold their shares on Friday losing half their stock equity.As an initial offer, UBS offered only $1 billion for Credit Suisse, which slowed down negotiations for a short time.