South Korea's antitrust watchdog said Sunday that it has fined two major security and safety service providers a combined 5 billion won (US$4.7 million) for hampering market competition through years-long covert cooperation.

S1 Corp., an affiliate of Samsung Group, and ADT CAPS were fined 2.5 billion won each for sharing their equipment in provincial regions with a promise not to compete against each other in those areas, according to the Fair Trade Commission (FTC). 

The equipment sharing took place from 2000-2002 in places where their security infrastructure was not well-established. The collusion not to compete continued for more than a decade, the FTC said. 

With such collusion, the two have dominated 95-100 percent of the market share in the regions, blocking competition from other smaller companies, the watchdog said.