The world’s biggest container shipping company Maersk Line, a unit of A.P. Moller-Maersk , said it plans to raise freight rates on routes from Asia to northern Europe by $400 per 20-foot container (TEU). The new rates will take effect from Sep. 1, the company said in a newsletter to shippers on Tuesday. Higher rates on the busiest freight routes between Asia and northern Europe would help companies, which have been struggling with overcapacity as a result of a weak global economy. Only a handful of container shipping companies posted profits last year. On average, shipping freight spot rates between Asia and northern Europe fell 7.7 percent to $1,106 per TEU in the last week ended on Aug. 22.