A 6.6 percent jump in container cargo volume over the prior year made last month the second busiest November in the 100-plus year history of the Port of Long Beach, officials reported Thursday.

Nearly 619,700 containers moved through the port, making it also the fifth month in a row of cargo volume growth when compared to year-ago periods, according to officials.

Much of the increase was from empty containers. The number of empty containers returning to overseas ports rose 19.5 percent over a year ago.

Imported container volume grew 4.3 percent while exports fell 4 percent. Officials attributed the drop in exports to the strong dollar.

Port officials cited retailers planning for post-holiday sales as the factor behind the jump in imported cargo numbers. They also said retailers who grew imports over recent months with holiday items are now sending back empty containers, accounting for the sharp increase in empties, officials added.

Officials said they expect cargo volume to exceed 7 million containers this year, the third time in the port’s history. The other two years were 2006 and 2007 when the port moved 7.29 million and 7.31 million containers, respectively. In this year’s 11 months, container volume is ahead of the year-ago period by 5.5 percent.

“Retailers have reported a modest but healthy holiday season, which keeps us busy and the economy growing,” said port Chief Executive Jon Slangerup.

The Port of Los Angeles said it expects to release cargo volumes by mid-next week.