PARIS — The launcher divisions of the French and European space agencies will be moving from their separate agency locales into a common office complex in Paris in late 2011 in an attempt to better coordinate the teams working on Europe’s rocket development strategy, officials from the two agencies said.

In the latest attempt to rationalize the dispersed government space efforts in Europe, the 220 members of the launcher directorate within the French space agency, CNES, will move from their longtime facility in Evry, France, into the new Paris quarters, a refurbished building near the Gare de Lyon train station.

The CNES teams will be joined by about 100 European Space Agency (ESA) officials, who will be decamping from ESA headquarters into the new facility.

CNES and ESA teams have worked in the same offices before on specific projects relating to rocket enhancements and, in the 1990s, a proposed crew vehicle that was later scrapped.

This time, the move will be permanent as the two agencies try to blend their overlapping roles. Through CNES, France has long paid about 50 percent of the development cost of the Ariane 5 rocket, which operates from French territory in French Guiana.

Following a failure of the Ariane 5 earlier this decade, CNES ceded the role of Ariane 5 prime contractor to Astrium Space Transportation, and its role of Ariane 5 contracting authority to ESA.

French Research Minister Valérie Pécresse said putting the CNES and ESA teams into the same offices “will put the demonstrated CNES expertise at the disposal of [ESA], and will allow us also to realize indispensable synergies.”

CNES Financial Director Laurent Germain said that in this case, “synergies” does not mean staff reductions, but simply a closer coordination as Europe manages, starting in 2011, the Vega small-satellite launcher and Russia’s medium-lift Soyuz vehicle alongside the heavy-lift Ariane 5 rocket at the Guiana Space Center spaceport.

ESA and CNES also will need to determine, in time for a 2012 conference of European space ministers, whether Europe should devote substantial resources to a successor to Ariane 5, or to an Ariane 5 Midlife Evolution vehicle with a restartable upper stage, or both.

The German government, whose industry stands to gain if a new upper stage is developed for the current Ariane 5 ECA rocket, is backing the midlife-extension project, estimated to cost 2 billion euros ($2.8 billion).

How much additional power the Midlife Evolution enhancements would provide compared with the current Ariane 5 ECA rocket is unclear. The design goal was to increase the rocket’s payload carrying capacity by 20 percent, to 12,000 kilograms, into the geostationary transfer orbit used by most commercial telecommunications satellites.

Also unclear is whether the modifications can be completed with no net increase in Ariane 5 operating costs. Astrium and Air Liquide said the Midlife Evolution stage could be ready for flight at the end of 2016.

Bremen, Germany-based Astrium and Air Liquide of France on Oct. 28 announced they would establish a joint venture to develop cryogenic fuel tanks for the Midlife Evolution upper stage. A new production facility will be built near Astrium’s Bremen facility, with construction beginning in 2011, the two companies announced. About 40 jobs will be created.

A preparatory program for Ariane 5 Midlife Evolution was agreed to in 2008 by European space ministers, but they reserved judgment on full program development until their next meeting, now set for 2012. Germany is financing 35 percent of this preparatory phase.

Astrium and Air Liquide already run a joint venture company, called Cryospace, that builds the cryogenic tanks for the Ariane 5 main stage.