By David Dolan JOHANNESBURG (Reuters) - South Africa's Standard Bank took an $80 million hit from its exposure to suspected metal financing fraud in China, wiping out first-half earnings growth at Africa's largest lender. Johannesburg-based Standard Bank, one several global lenders ensnared by the scandal at the Qingdao port, said on Thursday it was still unclear if further writedowns would be needed given a lack of available information from China. Chinese authorities launched an investigation in May into whether metals trading firm Decheng Mining and related companies used fake warehouse receipts at Qingdao port to obtain multiple loans secured against a single cargo of metal. "For us this is a very unfortunate event and something that we clearly weren't bargaining on or went looking for," co-Chief Executive Ben Kruger told Reuters Insider in an interview. He said Standard Bank would have achieved a 12 percent increase in first-half headline earnings per share were it not for the writedown. First-half diluted headline earnings per share edged up 0.6 percent to 507.7 cents. The bank took an 854 million rand ($80 million) "valuation adjustment" against financing agreements known as repos related to physical aluminium held in warehouses in China. When asked about the risk of a further impact, Kruger said: "It's too early for us, we have no information, really. We're not allowed into the ports like all of the other lenders". The bank, which is 20 percent owned by Industrial and Commercial Bank of China (ICBC), has started proceedings over its rights to the physical aluminium and said its total exposure related to the port was $167 million. The writedown will also impact the proceeds from Standard Bank's $765 million sale of its London-based global markets business to ICBC, investment banking head David Munro said. London-based Standard Chartered Plc said this month it had taken a $175 million provision to cover its exposure to the Chinese port. Standard Bank has been pushing into fast-growing sub-Saharan markets to offset chronic weakness in South Africa's economy. It said the outlook for its home market remained grim, with consumers hit by higher food and fuel costs and waves of strikes denting the confidence of company managers. "Sluggishness in the South African economy is expected to persist for the remainder of 2014, which is likely to hamper domestic revenue growth and may affect the confidence of our customer base," it said in a statement. Shares of the bank were down 1.7 percent at 143.38 rand at 1139 GMT. Headline earnings, the main measure of profit in South Africa, exclude certain one-time items.