Two-thirds of Brazilian Army M113 armored personnel carriers earmarked for modernization have been upgraded by BAE Systems.

BAE Systems called the recent upgrade of the 100th M113 to the M113A2 Mk1 configuration a "milestone" for Brazil under a 2011 contract that involved the use of local companies and technology transfer arrangements for vehicle maintenance.

"This is an important milestone for BAE Systems and our long-standing partner, the Brazilian Army," said Adam Zarfoss, director of Artillery and Recovery Vehicles at BAE Systems. "The delivery of the 100th upgraded vehicle is a direct result of our close working relationship with the army, developed through a strong technology-sharing program."

The A2 variant features an improved engine cooling system and power train, the addition of grenade launchers and extra fuel tanks among other enhancements. It is capable of amphibious operations, carries a dozen soldiers and is capable of extended cross-country travel over rough terrain.

More than 40 countries operate M113 variants.