By Julien Ponthus and Saikat Chatterjee LONDON (Reuters) -The British pound climbed on Wednesday for a fourth session in a row, reaching a 1-1/2-week high against the dollar, as investors firmly held to their expectations that the Bank of England will raise interest rates on Thursday. Investors have now fully priced a 25-basis-point rise in the BoE’s main interest rate to 0.50% on Feb. 3 and economists polled by Reuters also expect that outcome from the meeting. In late afternoon trading in London, the pound was up 0.36% at $1.3575 , its highest level since Jan. 21. At 83.27 pence for a euro, …