AltAssets:Chicago-based private equity firm GTCR Golder Rauner said it has agreed to sell Dallas-based TransFirst, a provider of transaction processing services and payment enabling technologies, to Welsh, Carson, Anderson & Stowe for $683 million. TransFirst processes approximately $25 billion in annual transactions for more than 155,000 merchants and 965 financial institutions. Originally founded as ACS Merchant Services in 1995, GTCR partnered with TransFirst to re-capitalize the company in 2000. Read more