Telecommunications giants Telstra and AAPT are facing up in Federal Court this week in a $700 million damages claim and counter-claim.
Telstra, which claims AAPT owes it more than $123 million for services provided between 1994 and 1997, initiated the proceedings, which are expected to last until late next year.
However, AAPT has counter-sued Telstra for what it claims are breaches of an agreement and negligence.
Initially, AAPT claimed $300 million, however, when the case kicked off yesterday, that figure had grown to $580 million, and is expected to increase even further.
The hearing continues.