Kingston Communications, which has served Hull for almost a century, wants to float on the stock exchange.

The BBC's John Thorne reports on the unique phone company

The firm - which offers its 185,000 customers the cheapest local calls in the country - is valued at £500m.

Its fate will be decided on Wednesday evening by the Labour councillors who control Hull City Council.

The company's origins date back to the turn of the century

The 97-year-old company, with its distinctive, old-fashioned cream-coloured telephone kiosks, wants to float on the exchange so that it can expand its operations in the telecommunications world.

It remains the only survivor of experiments with town hall phone systems at the turn of the century and has grown into a profitable international telecommunications business.

However it needs to raise half a billion pounds if it is to compete with the major players and the amount of public money the city council can spend is restricted.

After months of speculation, financial advice and political manoeuvering, the firm's only shareholder - Hull City Council, is expected to agree to sell at least part of Kingston Communications so that fresh investment funds can be found.

Kingston customers can get the cheapest calls in the country

The council has fought to retain what it calls "social ownership" but Government pressure and the company's ambitions in the global field of optic fibres, satellites and computer communications has made a change of status inevitable.

Professor Cosmo Graham of Hull Law School said: "It is clearly the end of an era now that they are being floated.

"They have been in local authority control since the turn of the century and there is a possiblity in the future of them losing their local monopoly."