Manx Telecom is about to list on the Alternative Investments Market, according to the Financial Times.
Liberum Capital and Oakley Capital will advise on the flotation, which could raise more than ?150 million depending on how much of the company is sold.
The telecoms provider founded in the late 19th Century, is majority owned by HgCapital after the group bought it from Telefonica in 2010.
Last year the company made a pre-tax profit of around ?25 million.
It's understood Manx Telecom's management team will begin holding discussions with City institutions before the end of January
The FT says the company could be valued at ?250 million in total on AIM, London's junior stockmarket.