By Rob Daniel,Tony Owusu United Healthcare saw an opportunity for efficiency. The antitrust authorities see improper industry consolidation. United Healthcare (UNH) – Get UnitedHealth Group Incorporated Report 13 months ago offered $8 billion for Change Healthcare, aiming to combine the Nashville company (CHNG) – Get Change Healthcare, Inc. Report with its Optum unit to offer software, data analytics and services to the industry. News reports, including from Bloomberg, at the time said the deal was to be one of the Minnetonka health-care giant’s largest acquisitions. The companies had said in …