Bangkok Medical Services (BMS), Thailand's largest hospital group, increase of its stake in Bumrungrad Hospital has triggered calls for tightening of Thailand's Trade Competition Act (TCA).  On 15 March 2012, the Bangkok Post reported that:

The government is under growing pressure to tighten the [TCA] to ensure the fair treatment of consumers and to strengthen the rules on mergers to ensure that consolidation does not result in market dominance to the detriment of competing businesses and consumers, particularly following the creation of the Asean single market. 

The TCA was enacted in 1999, and a summary of that law can be found here. There have been calls to amend the TCA, particularly Section 28 of the TCA, which sets out a catch-all and, many would argue, ambiguous and undefined prohibition on "unfair" practices. There have also been calls to enact a new, tougher trade competition law from scratch, but no such legislation has been enacted…yet.