LONDON, Dec 17 (Reuters) - The Bank of England said on Thursday it planned to keep the pace of its purchases of British government bonds broadly unchanged early next year. Including the reinvestment of the proceeds of a gilt that matures in January, the BoE said it planned to buy 4.44 billion pounds of gilts per week through January. As part of a 150 billion pound expansion of the quantitative announced in November, the BoE plans to raise its holding of gilts to 875 billion pounds. (Reporting by Andy Bruce, editing by Estelle Shirbon)