The US will likely suffer the loss of its triple-A credit rating from another major rating agency by the end of this year due to concerns over the deficit,Bank of America Merrill Lynch forecasts. The trigger would be a likely failure by Congress to agree on a credible long-term plan to cut the US deficit,the bank said in a research note. A second downgrade either from Moodys or Fitch would follow Standard & Poors downgrade in August on concerns about the governments budget deficit and rising debt burden. A second loss of the countrys top credit rating would be an additional blow to the sluggish US economy,Merrill said. The credit rating agencies have strongly suggested that further rating cuts are likely if Congress does not come up with a credible long-run plan to cut the deficit,Merrills North American economist,Ethan Harris,wrote in the report. Hence,we expect at least one credit downgrade in late November or early December when the super committee crashes, he added.