By Mehreen Zahra-Malik ISLAMABAD (Reuters) - Anti-government protests that have gripped Islamabad since mid-August could throw off course economic reforms Pakistan promised to deliver in return for an IMF bailout, senior officials said, raising the risk of a sovereign rating downgrade. The International Monetary Fund (IMF) saved Pakistan from possible default last September by agreeing to lend $6.6 billion over three years, conditional on reforms such as a longstanding pledge to privatize loss-making state companies. "The IMF folk think that if we can wrap this crisis up in a week or so, things will remain on course and normal. But if it goes on any longer, then, yes, we will be in trouble." Commerce Minister Khurram Dastgir Khan voiced concern that an IMF team had already canceled a visit to Pakistan because of the protests that turned violent last week as Prime Minister Nawaz Sharif refused to resign.