Analysts said it was the terminal's lowest monthly container volume handled so far this year and the slowest monthly growth compared with the previous year since October 2009.
But container volumes handled in the six months to June 2010 were up almost 25 percent to 1,010,087 TEUs compared with the same period in 2009.
Cargo volumes at Colombo port terminals, including the state-run terminals, have been recovering fast this year from a slump last year caused by global recession.
But the port suffered problems in June caused by a break down in trucking boxes between terminals and bad weather that delayed ships and slowed down cargo operations.