According to ITV News Central, Arena Coventry Limited are to sue Northampton Town FC.
ACL are understood to be taking legal action for what amounts to 'stealing' its customers.
The news comes following the announcment that Coventry City have agreed to play at Northampton Town's Sixfields Stadium for the next three years with the option of another two one year deals.
Northampton had responded by saying; "We are aware of the correspondence and have no comment to make."