PARIS — French defense electronics group Thales has agreed to purchase SESO, a small precision-optics manufacturer, in a move that will augment Thales’ in-house ability to produce satellite optical sensors through its majority-owned Thales Alenia Space satellite manufacturing unit, Thales announced.

Financial terms were not disclosed. SESO — a French acronym for European Optical Systems Co. — is expected to report about 12 million euros ($16 million) in revenue in 2010, 80 percent of it from customers outside France.

Aix-en-Provence-based SESO supplies mirrors and telescopes for satellite-borne optical instruments. Its hardware is aboard France’s two Pleiades high-resolution optical satellites, to be launched in 2011, and is slated for the two CSO optical reconnaissance satellites under construction for the French Defense Ministry.

Cannes, France-based Thales Alenia Space is prime contractor for most of France’s optical satellite instruments, usually in tandem with Astrium Satellites, which builds the satellites’ platforms.

SESO also has helped South Korea’s government develop its Kompsat series of Earth observation satellites.

SESO’s other business lines include high-power lasers and ground-based optical telescopes.

“There is a clear potential for synergies in very-high-resolution optics, a field where SESO has already achieved international acclaim,” Thales Optronics Business Director Serge Adrian said in a statement.

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