HSBC said on Wednesday it had sold the stake to an affiliate of Thailand's Charoen Pokphand Group CP Group, a conglomerate controlled by Dhanin Chearavanont, Thailand's richest man.

The price was equivalent to HK$59 per Ping An share.

The acquisition will be financed partly in cash and under a facility with China Development Bank Corp. Hong Kong.

Ahead of the sale, Mizuho Securities had estimated it could earn the bank a pre-tax profit of up to $6.5 billion.

The sale was expected as part of HSBC's three-year recovery plan after the 2008 financial crisis and regulatory reforms.

The bank had spent $1.7 billion to build the 15.6 percent stake in China's second-largest insurer between 2002 and 2005. It confirmed it was in talks to sell the stake on Nov. 19, after the Hong Kong Economic Journal reported the impending sale.

HSBC has embarked on a global plan to divest various holdings as it seeks to improve its profitability.

The Ping An stake, given its size, was an important and sensitive sale for the bank - one that was rumoured to be up for grabs ever since the 2008 financial crisis.

The deal was personally overseen by a three-man team headed by HSBC CEO Stuart Gulliver.

Analysts expect HSBC's stake in Bank of Communications (BoCom), China's fifth-largest lender, to be next on the list. That stake stands at 19.9 percent and is worth about HK$79 billion, according to Thomson Reuters data.

Forbes magazine says Thai tycoon Chearavanont, who owns unlisted CP Group, Thailand's largest food and agricultural business, is worth $7.4 billion.

Founded in 1988 as China's first joint-stock insurer, Ping An has grown into one of the world's largest, with 74 million clients, more than 175,000 employees, and about 500,000 agents.