Fonterra said it had asked the NZX for its shares and units to go on a trading halt this morning pending an announcement tomorrow about its capital structure.
The exchange has approved its request.
The trading halt would provide Fonterra shareholders and unit holders a full day to review and consider the materials before trading recommences.
"Following tomorrow's announcement, the trading halt will remain in effect until the market opens on Friday 7 May, to provide Fonterra shareholders and unit holders a full day to review and consider the materials before trading recommences," Fonterra said.
The co-op said it remained in a strong financial position and that the consultation process would not affect the co-operative's ability to operate.
Fonterra chairman Peter McBride told the Herald in March that fast-emerging challenges in the next 10 years made it essential for Fonterra to look at its capital structure now - despite some shareholders' views that no change was needed.
"I've heard the 'if it's not broken, don't fix it' [view]. So do we wait until it's broken? That's my response.
"As we start to share with them the challenges we see in the next decade I think sentiment will change."
McBride noted 62 per cent of the 1800 farmer-shareholders who responded to a survey on the capital structure review had strongly or slightly supported change.
Fonterra is owned by 10,000 shareholders, who each received an individual version of the survey.
McBride's kept his cards close on what capital structure reform may look like.
Fonterra's NZX-traded units last traded at $4.60.