CI╔ is being threatened with court action arising out of the company's attempt to install the mini-CTC rail signalling system.
CI╔ group solicitor Mr Michael Carroll told the inquiry the threat came from the liquidator for one of the two companies which had the contract to install the system.
The contractor, cabling company Modern Networks Limited (MNL), was jointly awarded the contract with signalling company Sasib in 1997.
Sasib, and its share of the contract, was subsequently taken over by Alstom Ltd, but the contract was terminated earlier this year.
Mr Carroll said CI╔ had settled its differences with Alstom but the liquidator for MNL, which went into liquidation in August this year, was threatening litigation.
He said he was confident about the outcome of any action as he believed the termination had been carried out within the terms of the contract.
The inquiry also heard optimistic opinion from senior CI╔ engineer Mr PJ Leahy about the legacy of the mini-CTC venture.
Mr Leahy said the project would be completed by CI╔ staff, although with different equipment than was used in the pilot installation at the Knockcroghery level crossing which, the inquiry has heard, suffered multiple faults.
Mr Leahy also said cables laid during a simultaneous project undertaken by CI╔ on behalf of telecommunications firm Esat, would be put to use.
The cable-laying venture, which allowed Esat create a national phone network, is being investigated by the inquiry after claims that it disrupted the mini-CTC project.
Mr Leahy said excess capacity on the cables could be used by CI╔ for non-commercial purposes such as closed-circuit television or public information systems.
CI╔ chairman Mr John Lynch made it clear he had no interest in developing the cable network for further telecommunications ventures. "Quite honestly, I have heard enough of telecoms to last the rest of my life," he said.