Italy's biggest telephone company Telecom Italia sought to allay millennium bug fears on Tuesday after sending a bill for the first two months of 1900. Telecom insisted its billing system was safe from the feared computer glitch and said the error appeared an isolated case. There are concerns that computer programmes, which record dates in two instead of four digits, could recognise the new year as 1900 instead of 2000. But Telecom recently upgraded all its software and has declared itself fully millennium compliant.