New Delhi, April 7 -- Air India chief executive Campbell Wilson has resigned but will stay on with the company till a successor is found, according to four people familiar with the matter. The development sets the stage for a leadership transition at a time when the airline faces operational disruptions, rising costs and a likely record loss this year. Wilson's resignation was accepted at a board meeting last week, these people said. "He will continue to be in the system until the board finds his successor --to help in a smooth transition--whenever that happens, until September," one of them said. Air India refused to comment on the matter. The search for a successor had begun in January after Wilson had expressed his wish to not continue a...