Clear Channel will now add the fourth-largest outdoor advertising company in the US to its own outdoor operation, which includes 700,000 displays.
The deal will also add 18 television stations owned or operated by Ackerley to its existing 19-strong TV network in the US.
In acquiring Ackerley, Clear Channel will take control of assets including: AK Media, the outdoor ad brand; TV stations including the New York-based WIXT News Channel 9 and WOKR News Source 13; as well as a network of radio stations in Seattle.
Clear Channel owns UK outdoor advertising company Adshel, as well as Clear Channel Outdoor in the US.
Earlier this year, Clear Channel landed what it claimed was the world's biggest outdoor advertising contract, after being appointed by French supermarket giant Carrefour to install billboards at its sites. The deal was worth €100m (£71m) over 10 years.
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