He replaces Andy Heathy who returned to CMG's London office after working in the Singapore job for six months.
The position involves managing a team of eight people working on Exxon Mobil's new loyalty programme for Esso and Mobil petrol stations.
The Smiles programme launched in Hong Kong last December and is scheduled to roll out in Singapore and Malaysia in the coming months.
Kool was previously deputy director of loyalty management at KLM Royal Dutch Airlines for nearly two years and before that held several other management positions at the Dutch carrier, which he joined in August 1997.
Kool said he was looking to relocate overseas and the position at CMG appealed to him.
He said being at an agency allowed him to work across several different industries so "it is broader experience and in that sense it is more intellectually challenging".
"My intention is to stay here for a long period. The challenge is to leave behind a legacy; very rarely do you get the opportunity to join an office with huge potential but one that is already equipped with lots of experience, he added.
Robert James, CMG president for Europe, interviewed Kool in December last year, and recommended him to Gerry Pereira, CMG Asia-Pacific president based in Singapore.
