OSLO (Reuters) - Norway's biggest bank DNB will expand its share buybacks in the near term and aims to cut costs by between 1.5 billion and 2 billion Norwegian crowns (£169 million) in the next three years, it said on Wednesday.Savings will come from initiatives in IT, distribution and automation, as well as structural changes, the bank said in a statement ahead of a strategy update in London.The company last month said it would buy back 0.5% of its shares by April of next year, but on..