<p>Jeffrey Immelt is stepping down as chairman and chief executive of General Electric Co., bringing to an end a tumultuous 16-year tenure in which he dramatically reshaped the manufacturing powerhouse but failed to win over Wall Street.</p>
<p>Amid mounting pressure from activist investor Trian Fund Management, GE said Monday that Immelt will be replaced by John Flannery, a 30-year company veteran who oversaw a jump in profits at the health-care unit. In a sign of just how great opposition to Immelt had become in the investing community, the stock soared the most in more than a year and a half after the announcement was made.</p>