Travelers Cos., the only property-casualty insurer in the Dow Jones Industrial Average, said fourth-quarter profit jumped 8.9 percent as investment income improved and the company recorded a gain tied to the settlement of a risk-sharing dispute. Net income rose to $943 million, or $3.28 a share, from $866 million, or $2.83, a year earlier, the New York-based company said Tuesday in a statement.