Dutch airline Martinair will drop its 747-200 freighters in favor of newer converted versions of the 747-400, the carrier announced.

The switch comes as rising jet fuel prices put growing pressures on the operating costs of older aircraft such as the 747-200s in Martinair's fleet and make the higher price-tag on the more recent aircraft more acceptable to carriers.

The 747-400s burn less fuel to operate than the 747-200s, and they have more capacity and greater range than the older planes.

Martinair flies two of the four-engine jumbos in full-freighter configuration, alongside two 747-200s it operates as convertible passenger-cargo aircraft. The airline says it will take the planes, to be converted by Boeing, by the end of 2006.

The airline's cargo revenue, which makes up about two-thirds of Martinair's overall revenue, jumped 16 percent in 2005 over the year before to US$870 million. Cargo traffic grew 5 percent, led by growth in Asia and the Americas.

Martinair's overall profit grew 40 percent to $17.2 million.