Dark Corporation by Ben Colt

A director intending to whistle blow on the Dark Corporation global security firm, mysteriously dies before meeting MI5.
Max Sargent has become a successful business Procurement Officer, with a distant and harrowing past in the Commandos. Following a business indiscretion, MI5 offer him clemency to find out what’s happening at Dark.
Max uses his corporate agility to uncover leads, whilst staying one step ahead of the controlling founder Frank Dark, who’s planning something big, and destructive. His assignment gets increasingly dangerous, taking him from the UK to India, Hong Kong and the Caribbean.
Discovering the involvement of a foreign Intelligence Service, Max finds himself being the only person with a chance of averting an impending global catastrophe.