Some Hawaiians will experience a card switcharoo next year. Cardholders of Bank of Hawaii's VISA credit cards will have them replaced with American Express credit cards. This week American Express announced its first agreement to acquire a U.S. bank credit card portfolio and to market AmEx cards and products to the bank's customers.  American Express signed agreements to acquire the VISA credit card portfolio of Bank of Hawaii. The BoH portfolio includes 148,000 consumer and business accounts, with receivables of approximately $226 million. Under terms of the agreement, AmEx will issue and market Bank of Hawaii-branded American Express Cards to the bank's customer base. The cards will be marketed through Bank of Hawaii in Hawaii and the West Pacific, and Pacific Century Bank in California, as well as through more than 500 ATMs and via direct mail. Bank of Hawaii card customers will receive information on the card transfer shortly. They will receive a new Bank of Hawaii-branded AmEx card, which they will be able to activate at the time of the transfer. Pricing terms and conditions will remain the same at conversion.  As with all credit cards, cardholders will have the option of paying their balances in full or in monthly installments. The transfer of the credit card portfolio is expected to be completed in the first or second quarter of 2001.