McNab has signed a two-year sponsorship deal with watchmaker Traser that sees him promote the watches in his thrillers.
The Traser's new website features pages and pages of McNab information, imagery and book reviews, to support the association.
McNab's latest novel 'Liberation Day' sees his hero Nick Stone take on Al-Qaeda and contains more than 60 references to Traser watches.
One passage in the book reads: "I dug my right knee into his left thigh. His cologne filled my nostrils and I saw a gold Rolex glint on his wrist. This boy had obviously never seen what a Traser could do for you."
One publishing source attacked the book, saying: "This turns books into cynical marketing and erodes reader confidences."
Traser watches are best known for their "permanent light technology", which allows them to be easily seen in the dark. They are widely used by the military and Traser offers discounts to the military.
McNab's deal is part of a rising trend in the book world of brand tie-ups. It follows Fay Weldon who recently named her book after the Italian jewellers Bulgari. The company paid Weldon to mention its brand in her work. Originially, Bulgari had paid Weldon an undisclosed amount to write a short work of fiction with at least 12 favourable mentions of the company.
However, Weldon took it a step further and released a new novel, 'The Bulgari Connection', last year.
The Bulgari sponsorship, like the McNab tie-up, did not go down well in literary circles. Critics warned it threatened the purity of the novel.
A spokesman for Traser said: "It's a perfect tie-in for us because Andy loves the watches and began using them while in the SAS."
McNab found fame with his book 'Bravo Two Zero', which told the story of an SAS patrol, of which he was a member, that was discovered by the Iraqis during the Gulf War.
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