BT pleaded guilty to four offences in breach of Section 65(1) and (4) of the New Roads and Street Works Act 1991, which places a duty on utility companies to carry out works on the highway safely.
The infringement occurred in June 2015, when a contractor working on behalf of BT began to repair a blocked duct at a signal-controlled junction.
BT were fined £4,000 and ordered to pay all court costs at Crewe Magistrates Court.
The court was told that a contractor for BT was working in an trench in line with a pedestrian crossing, which was still being used by pedestrians. Insufficient management meant that pedestrians and road workers were not safely separated from passing traffic.
This created a dangerous situation for people with disabilities, the elderly, children and those with pushchairs.
A highways inspector from Cheshire East Council ordered the site to be cleared immediately and BT was prosecuted and taken to court.
Councillor David Brown, Deputy Leader and Cabinet member for highways, said: "This case proves the effectiveness of our permit scheme in the monitoring and enforcement of third-party road works.
"We are committed to ensuring our residents remain safe when they travel around Cheshire East. Hopefully this case will remind utility providers about the absolute need to work safely on the network."
The Cheshire East highways permit scheme was implemented in November 2014 and aims to promote better planning, coordination and monitoring of roadworks.