The Northern Ireland Assembly Commission is being sued in a dispute over a lucrative contract to provide broadcasting services at Stormont.
Lawyers for Belfast-based production company, Macmillan Media, have served a writ on the commission.
They claim it breached public contract regulations by awarding the contract - estimated at £2m - to rival firm, Pi Communications Ltd.
Macmillan Media originally held the contract.
It was responsible for the provision of video, sound and broadcasting services on behalf of the Assembly.
The contract later switched to Pi Communications on a five-year deal which is due to run out this summer.
Following a new tendering process, Pi Communications was again identified as the successful bidder.
But this decision has now been suspended after High Court proceedings were initiated.
Macmillan Media is seeking a declaration that the Assembly Commission acted in breach of its obligations under the Public Contracts Regulations 2006.
It is also arguing that the decision is ineffective and should be set aside.
A further alternative damages claim has been included for losses sustained as a result of the defendant's alleged breach of its obligations.
A writ was served on the Assembly Commission this week giving them 14 days to enter an appearance in response to the action.
An Assembly spokesperson said: "The Northern Ireland Assembly Commission can confirm that proceedings have been instigated but due to the fact that the litigation is currently ongoing, the Northern Ireland Assembly Commission does not wish to comment further at this stage."
A spokesman for Macmillan Media declined to comment.
