PARIS — Space system prime contractor Astrium of Europe has agreed to purchase a majority stake in satellite antenna and ground segment manufacturer Space Engineering SpA of Rome in a transaction that will boost Astrium’s presence in Italy, which is Europe’s third-largest space investor, Astrium announced Dec. 21.

Under the agreement, Astrium will acquire 66.78 percent of Space Engineering, which with its Teleinformatica e Sistemi subsidiary employs about 150 people in Rome and Tito, Italy. Financial details of the deal were not disclosed.

Space Engineering was founded in 1989 by four engineers and has since grown into a company whose customers include the European and Italian space agencies and Italy’s Ministry of Defense.

The 19-nation European Space Agency (ESA) awards contracts using the principle of geographic return, in which a given nation’s national industry will receive program contracts on a par with the government’s investment in the program. Italy is ESA’s third-largest contributor after France and Germany.

Astrium and Europe’s two other satellite system prime contractors, Thales Alenia Space of France and Italy, and OHB AG of Germany, in recent years have been picking up ownership stakes of smaller companies located in nations whose ESA contributions and national space programs make it important to have a local address. Thales Alenia Space and OHB both have a major presence in Italy.

Astrium’s principal installations are in France, Germany, Britain and Spain.

“Space Engineering will further strengthen our portfolio, enabling us to provide cutting-edge digital telecommunications and RF technologies,” Astrium Chief Executive Francois Auque said in a Dec. 21 statement announcing the purchase. The acquisition is pending review by European antitrust authorities.

Peter B. de Selding was the Paris bureau chief for SpaceNews.