A Multiple System Operator or Multi System Operator (MSO) is an operator of multiple cable television

Cable television

Cable television is a system of providing television programs to consumers via radio frequency signals transmitted to televisions through coaxial cables or digital light pulses through fixed optical fibers located on the subscriber's property, much like the over-the-air method used in traditional...

 systems. A cable system in the United States, by Federal Communications Commission

Federal Communications Commission

The Federal Communications Commission is an independent agency of the United States government, created, Congressional statute , and with the majority of its commissioners appointed by the current President. The FCC works towards six goals in the areas of broadband, competition, the spectrum, the...

 (FCC) definition, is a facility serving a single community or a distinct governmental entity, each with its own franchise agreement with the cable company. Though in the strictest sense any cable company that serves multiple communities is thus an MSO, the term today is usually reserved for companies that own a large number of cable systems, such as Time Warner Cable

Time Warner Cable

Time Warner Cable is an American cable television company that operates in 28 states and has 31 operating divisions...

, Cablevision, Comcast

Comcast

Comcast Corporation is the largest cable operator, home Internet service provider, and fourth largest home telephone service provider in the United States, providing cable television, broadband Internet, and telephone service to both residential and commercial customers in 39 states and the...

, Charter Communications

Charter Communications

Charter Communications is an American company providing cable television, high-speed Internet, and telephone services to more than 4.7 million customers in 25 states. By revenues, it is the fourth-largest cable operator in the United States, behind Comcast, Time Warner Cable, and Cox Communications...

 and Cox Communications

Cox Communications

Cox Communications is a privately owned subsidiary of Cox Enterprises providing digital cable television, telecommunications and wireless services in the United States...

 in the US, Rogers Communications

Rogers Communications

Rogers Communications Inc. is one of Canada's largest communications companies, particularly in the field of wireless communications, cable television, home phone and internet with additional telecommunications and mass media assets...

, Videotron

Vidéotron

Vidéotron GP is a Canadian integrated telecommunications company active in cable television, interactive multimedia development, video on demand, cable telephony, wireless communication and Internet access services. Currently, the company primarily serves Quebec, as well as the francophone...

 and Shaw Communications

Shaw Communications

Shaw Communications is Canada's largest telecommunications company that provides telephone, Canada's fastest Internet and television services as well as broadcasting and soon Wifi. Shaw is headquartered in Calgary, Alberta...

 in Canada or Virgin Media

Virgin Media

Virgin Media Inc. is a company which provides fixed and mobile telephone, television and broadband internet services to businesses and consumers in the United Kingdom...

in the UK.

Top MSOs Worldwide by Number of Subscribers

Rank	Country	MSO Name	# of Subscribers
1	USA	Comcast Corporation	22,525,000
2	USA	Time Warner Cable	12,235,000
3	EMEA	UPC Broadband (9 in Europe)	9,100,000
4	Germany	Kabel Deutschland	8,900,000
5	USA	Cox Communication	4,838,000
6	USA	Charter Communications	4,413,000
7	UK	Virgin Media	4,772,800
8	China	Beijing Gehua	4,000,000
9	France	Numericable	3,500,000
10	Japan	J:Com	3,300,000
11	USA	Cablevision Systems Corporation	3,284,000
12	Belgium	Telenet	2,300,000
13	Germany	Kabel BW	2,300,000
14	Canada	Rogers	2,295,000
15	USA	Bright House Networks	2,139,000
16	Canada	Shaw	2,241,503
17	Spain	ONO	1,823,536
18	Sweden	Com Hem	1,760,000
19	Switzerland	Cablecom	1,670,000
20	Canada	Videotron	1,652,200
21	Netherlands	Ziggo	1,600,000
22	China	Jinan Cable Network	1,300,000
23	USA	Suddenlink Communications	1,274,000
24	USA	Mediacom Communications Corporation	1,139,000
25	Taiwan	Kbro	1,150,000
26	Taiwan	CNS	1,100,000
27	Canada	Star Choice	886,106
28	Canada	Cogeco	859,090
29	Australia	Austar	742,000
30	Poland	Vectra S.A.	740,000
31	USA	Insight Communications Company	680,000
32	Taiwan	TBC	700,000
33	USA	CableOne	637,000
34	Taiwan	TFN media	550,000
35	Poland	Multimedia Polska S.A.	506,000
36	Cyprus	Cablenet Communications	25,000

External links

http://www.ncta.com/Stats/TopMSOs.aspx - National Cable & Telecommunications Association, Top 25 MSOs as of June, 2011