Shares in British Telecommunications Plc were down sevenpence at 436.5 pence after touching 435 pence yesterday on the publication by the Office of Telecommunications of its ruling on interconnect rates: under the new rules, British Telecom’s competitors will get a list of standard charges next January showing how much they must pay to use the network, and in the meantime will get a ready reckoner giving costs and overheads, which they can use to calculate the charges they face for interconnection – that is stage one; under stage two, starting this month, British Telecom’s operating licence will be amended, and January will see the introduction of a list of standard interconnection charges and separation of accounting for the various parts of British Telecom’s business – it will have to account separately for its network and retail operations thus ensuring transparancy on its costs for providing interconnect services; work has already started on stage three, which will include further consideration of a range of complex, and often conflicting, issues such as alternative concepts of cost assessment, charging structures and the range of services which should be offered; British Telecom said it ‘regrets that Oftel have chosen from the various possibilities a costly increase in regulation of British Telecom at a time when government attention is focused on deregulation, saying that it proposed and would have preferred accounting separation and rules that dealt with the telecommunications industry as a whole, and not just British Telecom selectively.