(Reuters) - Singapore's anti-trust regulator blocked a takeover for the first time when it provisionally ruled last week that Malaysian IHH Healthcare Bhd's planned purchase of a local unit of India's Fortis Healthcare would lessen competition.

The proposal by IHH Healthcare, Asia's largest hospital operator by stock market value, to buy Radlink-Asia Pte Ltd for S$137 million ($98.4 million) fell through after the ruling, Fortis said on Friday.

The Competition Commission of Singapore (CCS), which informed the companies of its decision on March 11, said in a statement on Monday that the proposed transaction would have resulted in a "substantial lessening of competition" in the affected markets.

Lawyers have previously said the CCS, which was established in 2005, is starting to ratchet up its enforcement policy and take on bigger cases. Last year it fined three Japanese manufacturers for taking part in a ball bearing pricing cartel and 10 freight forwarders for price fixing.