London: Saudi Arabia’s Prince Al Waleed has insisted his high court libel action against the business magazine Forbes is “not about ranking on some list or personal wealth”.

Al Waleed, who is one of the world’s wealthiest businessmen, is suing Forbes in London over an article published alongside its coveted Rich List, which he claims underestimated his fortune by $9.6 billion.

The billionaire said he is seeking damages from the magazine over “seriously defamatory comments” about him and his investment vehicle, Kingdom Holdings Company, which owns stakes in Rupert Murdoch’s News Corporation and London’s Savoy hotel.

In the first official statement since the Guardian revealed his libel claim last week, Al Waleed’s office said: “The basis for actively pursuing a legal action against Forbes would not be about ranking on some list or personal wealth, it is about correcting seriously defamatory comments that have been made about HRH Prince Al Waleed as an individual and Kingdom Holding Company.”

The prince accused Forbes of publishing a “deliberately insulting and inaccurate” description of the Saudi Arabian business community and said it had “denigrated” the country’s stock exchange, the Tadawul.

In its article in March, Forbes quoted a former Al Waleed executive who described the Tadawul as a gambling site. The magazine said it calculated his fortune at $20 billion, placing him at 26 on its Rich List, after valuing the underlying investments of Kingdom Holding Company instead of its shares traded on the Tadawul.

However, Al Waleed said this amounted to Forbes accusing him of market manipulation. In a tersely worded statement, the royal said his legal action was a “necessary and appropriate response” to Forbes’s “irrational and deeply flawed valuation methodology, which is ultimately subjective and discriminatory”.

The libel writ has been filed at London’s high court by the law firm Kobre Kim, which describes itself on its website as “Aggressive. Global. Conflict-free.”

In a statement, Forbes said it continues to be “bemused by Prince Al Waleed’s ego-driven PR stunt”. It added: “Forbes still has not been served with any lawsuit. Our story raises significant questions about his finances, and we would welcome the opportunity to uncover further relevant information during the course of any hypothetical suit.”