The Port of Los Angeles imported and exported more container units last month than any June in its history. The nearby Port of Long Beach reported similar gains.

More than 730,000 container units were handled, up about 32 percent from last June, which represented a 15 percent increase for the first six months of 2010 compared to the same period last year. L.A. port spokesman Phillip Sanfield said Tuesday.

“What we’re seeing is a strengthening of the overall trade environment,” said Sanfield, adding that the June numbers represented the fourth monthly increase in a row. “We’re pleased because it’s stronger than we had forecast.”

He was cautious, however, in characterizing the numbers as a recovery.

“What we need is a 12-month period of growth,” he said. “This is a good start – perhaps the beginnings of a recovery – but I don’t think it’s enough yet to say that we’re in recovery mode.”

The Long Beach reported a 25.8 percent increase in container units handled in June, which was the seventh increase in as many months. Overall imports were up 27 percent while exports rose 1.8 percent, bringing the total number of containers handled to 520,100.

“This clearly means that we’ve moved way beyond the depths of recession from a year ago, though it will be very difficult to sustain at this level,” Long Beach port spokesman Art Wong said.

Because of lingering high unemployment, slow job creation and cautious consumer spending, Sanfield said, the large monthly growth rate may not continue. “We’re hearing that the second half of the year could flatten out,” he said. “While we are encouraged by the first six months of growth, we realize that it’s really a month-to-month situation.”