Meat processing company AFFCO and the Meat Workers Union have concluded their two-day mediation but no resolution has been reached.
Industrial action has been going on for months as the parties try to agree on a collective contract.
AFFCO has locked out up to 900 workers, but on Tuesday has lifted the notice allowing 300 employees to return to work on Wednesday.
The union says those workers will probably strike in support of their colleagues.
Further bargaining talks have been set up for Monday and Tuesday next week.
An Employment Court hearing on the legality of the lockout has been set down for 16 May.