Associated Television, or ATV, was one of the first commercial television companies to go on the air in the United Kingdom. They launched in London on September 24, 1955. As it turned out, they became the second commercial television station to go on the air in the country, narrowly beaten by another company called Associated-Rediffusion which launched two days before.
Incidentally, the company wasn't called ATV when it launched. It was initially referred to as the Associated Broadcasting Company, or ABC for short, but had to change its name after another broadcaster claimed those initials. So the company promptly had to come up with an altered name an change its logo to include the new initials.
The basic shape of the logo seen above was used from the start, minus two of the letters that were added later. That didn't change the idea behind the logo, an eye shape and its shadow, looking a bit like the classic CBS logo. The ATV logo is attributed to John B. Castle, a designer at Colman Prentis & Varley, which was ATV's ad agency in the early days. Mr. Castle remains largely unknown today, although he was a member of the Designers and Art Directors Club.
Above is an early example of a trade advertisement from 1955, alerting advertisers of the power of television. Note that it uses the original version of the logo with "ABC Television" lettering.
Below is ATV's colour ident, shown before programmes.
ATV remained in business for 26 years, producing many classic British television series. Many of them were also exported, the most famous example being The Muppet Show. By the early 80s, ATV fell out of favour of the regulator and didn't have its license extended. The company continued using the shadowed eye logo for all those years.
For more on ATV and its presentation, visit TV Ark and Transdiffusion.