Timothy Donahue is about to rejoin his old firm J.P. Morgan in a senior role on the loan and high-yield capital markets desk in the US -- an area where the bank, as one of the key survivors of the financial crisis, is currently boasting a dominating market share, sources familiar with the situation say.Donahue will return to the US after about three years in Asia and, according to the sources, he will leave the region as soon as the end of this week to take up his new job, which will see him rejoin the same team that he left in April 2006 to come out here. He will assume the ...