(Reuters) - JPMorgan Chase & Co (JPM.N) posted a 23 percent increase in quarterly profit as a stabilizing labor market helped ease losses on consumer loans. The bank's shares edged lower as its loan books shrank and investment banking profits fell, raising questions about whether it can post robust profit growth in future quarters. JPMorgan is the first of the major banks to report third-quarter results, and the figures show how mixed a quarter this was for the financial sector. While loan losses are improving, trading businesses are flagging and upcoming quarters could be weak. JPMorgan Chief Executive Jamie Dimon sounded cautious notes about the future, noting that client activity in investment banking is muted because of uncertainty about the economy. Read More: Source Reuters