Standard Chartered's headquarters in London: The bank earns most of its revenue in Asia and Africa. © ReutersHONG KONG/LONDON (Reuters) -- Standard Chartered reported on Wednesday a better-than-expected 9% rise in first-half pretax profit and lifted its full-year income target, as wealth and global banking revenue surged and credit charges tied to the Iran war held steady.The bank's Hong Kong-traded shares rose more than 5% after the earnings release to hit an almost 19-year high.StanChart, which earns most of its revenue in Asia and Africa, said that pretax profit for the first six months of this year reached $4.78 billion. That compared with $4.38 billion a year earlier and the $4.52 billion average of 16 analyst estimates compiled by the bank.The bank revised its guidance for the year, saying it would see income growth around the middle of a 5-7% range instead of previous guidance for it to be closer to the bottom.Wealth management income jumped 38%, driven by double-digit growth in investment products as inflows and the number of new accounts increased amid strong demand for wealth advice during a period of market volatility."Clients continue to turn to us to facilitate trade, investment and wealth flows across the world's most dynamic markets," Group Chief Executive Bill Winters said in a statement.StanChart said its Middle East portfolio represents 6% of overall exposures, and that it had remained broadly stable.The lender took a $44 million additional impairment in the second quarter, which it said partly reflected clients in the petrochemical sector showing early signs of distress.It set aside $190 million as precautionary management overlays in April against expected future losses.StanChart announced a $1 billion share buyback, along with an interim dividend of 20.4 cents per share, up from 12 cents the year before.