"Either merger would make it more difficult for other exchanges to compete with LSE in trading UK equities due to both bidders direct control or influence over the provision of clearing services, " it added.

BBC: The watchdog's report could spark further bids for the LSE

Across the country, Blue Cross plans are often leaders in their markets in the provision of individual benefits as well as small group plans for small and medium-sized businesses as they compete with the likes of UnitedHealth Group (UNH), Aetna (AET) and Humana (HUM) for these new customers.

FORBES: Health Insurers Will Be Ready For Obamacare Exchanges, Blue Cross CEO Says