U.S. firms are pushing ahead with plans to open bitcoin exchanges catering to professional traders, after the closing of a Tokyo-based exchange sent shock waves through the virtual-currency world.

Perseus Telecom, a provider of high-speed telecommunications lines for securities exchanges and trading firms, is joining forces with bitcoin-trading platform Atlas ATS and Strevus Inc., which produces compliance-management tools for financial institutions and other firms, to build one or more U.S.-based digital-currency exchanges...