There are lots of satellite manufacturers all over the world.
The most important ones (of geosynchronous satellites) are Thales
Alenia Space (from Italy and France), JSC Information Satellite
Systems (in Russia), Boeing (USA), Astrium (a European consortium
in France, Germany, Spain, and UK), Lockheed Martin (USA), and
Space Systems / Loral (USA).
Among satellite platform manufacturers (listing is far from
complete) are Amsat (international consortium USA, Canada, etc.),
Ball Aerospace (USA), British Aerospace (UK), Fairchild (USA),
Fokker (Netherlands), General Electric (USA), Hawker Siddeley (UK),
Hughes (USA), IHI (Japan), Khrunichev (Russia), Mitsubishi (Japan),
Northrop (USA), Philco Ford (USA), Rockwell (USA), RKK Energiya
(Russia), SPAR Aerospace (Canada), Surrey Satellite (UK), Yuzhnoye
(Ukraine).
Launch vehicles (rockets in non-technical language; listing not
complete) are from Arianespace (Europe), EADS (Europe), ISC
Kosmotras (Russia) Space Quest (USA), Space X (USA), Starsem
(Europe), United Launch Alliance (USA), Yuzhmash (Ukraine).
The satellites are owned by the various space agencies,
international organizations (e.g. Eumetsat) or private operators
(telecommuncation agencies).