An index measuring San Diego’s economy increased 0.6 percent in September, following an upward trend for much of the past 12 months.

The USD Burnham-Moores Center for Real Estate’s Index of Leading Economic Indicators for San Diego County showed all six of its components rising, with the strongest gains in building permits and the national economic index. Local stock prices increased modestly, and the three other components — initial claims for unemployment insurance, consumer confidence and help wanted advertising — made slight gains.

Alan Gin, the USD economics professor who compiles the data for the index, said a solid gain last month combined with the fact that all six components were positive alleviates some of the concerns generated by the August report, which was revised to 0.1 percent decrease instead of the earlier reported flat rate.

Gin cited the latest jobs report showing a net gain of 28,000 jobs for the area through September as evidence of a slow but steady recovery. “Job growth is expected to remain solid for the rest of the year and at least through the first half of 2013,” Gin said.