Updated

Exports from California remained strong in June, growing from the previous year for the 20th month in a row.

The increase reported Thursday highlights one of the state's most consistent bright spots in the struggling economy.

California still has the second-highest unemployment rate in the nation and job growth has been spotty, but exports have returned to pre-recession levels after adjusting for inflation.

The report by Beacon Economics, done by analyzing U.S. Department of Commerce data, said export growth gives companies a reason to invest at a time when uncertainty has made businesses reluctant to spend.

Exports by California companies totaled $13.8 billion in June, up 13 percent from a year earlier. Exports for the first six months of the year also were up by about 13 percent from the first half of 2010, Beacon reported.

"The primary source of growth for the U.S. over the past year has been through the export sector," said Christopher Thornberg, a partner at Beacon.

There was a different picture for state imports. The number of shipping containers arriving at California ports dropped 5.5 percent from the same period last year, while imported air cargo tonnage fell 11.7 percent.

Imports had been up on a year-over-year basis until June, but the amount of growth had been shrinking, said Jock O'Connell, international trade adviser to Beacon.

"All five major ports of entry were down and it really reflects the stagnant state of the U.S. economy," O'Connell said. The lower value of the U.S. dollar, which makes exports cheaper and imports more expensive, also was a factor.