NEW YORK, May 22 (Reuters) - A year ago, Jeff Immelt told investors at an industry conference there was a "mismatch" between the performance of company he led, General Electric Co, and its stock price. Immelt, whose departure as chief executive was announced last June, proved prescient but perhaps not in the way he was thinking: GE shares have declined 45 percent since that conference and hit a nearly nine-year low in March. On Wednesday, Immelt's successor as chief executive of the industrial conglomerate, John Flannery, will make the case for GE's investment potential at the same annual Electrical Products Group investor conference in Longboat Key, Florida. Flannery will have some momentum. The stock price has climbed 20 percent since early April, and GE on Monday clinched a deal to spin off its transportation unit. But, at around $15.50 a share, the stock is still well in the red for 2018, down 11 percent.