London CNN  —  Switzerland’s biggest bank, UBS, has agreed to buy its ailing rival Credit Suisse in an emergency rescue deal aimed at stemming financial market panic unleashed by the failure of two American banks earlier this month. “UBS today announced the takeover of Credit Suisse,” the Swiss National Bank said in a statement Sunday. It said the rescue would “secure financial stability and protect the Swiss economy.” UBS is paying 3 billion Swiss francs ($3.25 billion) for Credit Suisse, about 60{9f99fe44fce1aa3c813d0a0ce4da2fbea8a5a58e9d85c4a2927dd8140cb676b5} less than the bank was worth when markets closed on Friday. Credit Suisse shareholders will be largely wiped out, receiving the equivalent of just 0.76 Swiss francs in…