Thales Alenia Space and the European Space Agency are seeking to improve the positioning signals delivered by the GPS satellite navigation system.

Development of improvements to EGNOS, or European Geostationary Navigation Overlay System, come under a three-year framework agreement announced on Friday.

EGNOS has been operational on European GPS satellites since 2009. Its "Safety of Life" service -- declared operational in 2011 -- allows it to be used for aircraft landing, enabling precision approaches to European airports without ground guidance aids.

"The signature of this framework contract with ESA ... marks a decisive new step for Europe's EGNOS navigation system," said Philippe Blatt, head of the Navigation business line at Thales Alenia Space France.

"We are already prime contractor for the Galileo (satellite) Mission Segment, the Galileo Security Facility and the Galileo system. This latest contract confirms Thales Alenia Space's position as the European leader in satellite navigation, a position we have held for over 20 years."

Under the agreement, the European Space Agency will be able to order work packages from Thales Alenia Space France to develop new versions of EGNOS V2. The new versions will ensure the continuous improvement of EGNOS performance, while also addressing obsolescence, Thales Alenia Space said.