JPMorgan profit up 34 percent with mortgage surge Fri Oct 12, 2012 9:35am EDT (Reuters) - JPMorgan Chase & Co said third-quarter earnings jumped 34 percent as the largest U.S. bank made more home loans. Net income was a record $5.71 billion, or $1.40 a share, up from $4.26 billion, or $1.02 a share, a year earlier, the bank reported on Friday. Results for both periods included special items. The company said it recorded a "modest loss" in the quarter on its so-called "London whale" derivatives portfolio, which had lost $5.8 billion this year through June. It said its Treasury and Chief Investment Office division, which formerly held all of the portfolio, may lose about $300 million more in the fourth quarter. Revenue from mortgage production was $1.8 billion, up 36 percent from a year earlier, excluding losses for buying back bad mortgage loans sold in the past to investors. U.S. banks have been enjoying a surge in demand from homeowners to refinance mortgage loans at lower interest rates. Reporting by David Henry, Jed Horowitz and Lauren LaCapra in New York; editing by John Wallace