The head of HSBC\'s Hong Kong unit is leaving his post after more than two decades at the British lender.The departure of Mark McCombe, who will become chairman of investment firm BlackRock\'s Asia-Pacific business, comes as HSBC pushes ahead with plans to shed 3,000 jobs in the city over the next three years.Anita Fung, the HSBC unit\'s general manager, will succeed McCombe as chief executive, the bank said late Friday. \"Ms. Fung succeeds Mark McCombe, who is leaving the bank to join another financial institution in Hong Kong,\" it said in a statement.HSBC last month announced plans to save up to $3.5 billion by 2013 and to axe 30,000 jobs globally by 2013.The Asia-focused bank has also said it will hire up to 15,000 people in emerging markets by 2014 as it looks to Asia\'s booming financial sector to power future growth, yet is still pushing ahead with the Hong Kong jobs cull.HSBC was founded in Hong Kong and Shanghai in 1865, although it remains headquartered in London.