"The company will treat employees with the utmost respect during this process and every effort will be made to support affected employees and their families.
"With the support of its parent company Kraft Heinz, Heinz Wattie's continues to invest significantly in its Hawke's Bay activities from growing to processing."
In November 2017, Heinz Wattie's applied to the commission and competition authorities in Australia and Singapore to acquire Cerebos Gregg's as part of an international transaction.
At the time the E tū union said it would take a wait-and-see approach to the move.
"That's because we are always nervous whenever Kraft Heinz buys any company, given its track record here and overseas," E tū union food sector industry co-ordinator Phil Knight said.
Knight said the union was in touch with members and was now aware of two proposals, one at King St and one at Tomoana St to reduce staff.
It was proposed to reduce staff levels by 40 at the King St premises, and another unknown number at the Tomoana site.
"We've basically entered into a consultation process. The main point for us is to actually get some information out of the company about what it is that's driving the proposal. Once we have that we can work with our members to determine a response.
"We know what's going on within the rest of the Kraft Heinz corporation, there's an international project - Project Phoenix - which is about finding efficiencies and reducing costs.
"We have been told that this is something that is in New Zealand now. Knowing what's happened overseas we're going into this with an open mind, and we hope the company is too."
In March, New Zealand's Commerce Commission granted clearance for Heinz Wattie's, which is ultimately owned by its NASDAQ-listed parent company Kraft Heinz, to acquire the food and instant coffee business of Cerebos Gregg's.
The Commerce Commission's decision is subject to a divestment undertaking from Heinz Wattie's.
The divestment will include licences for the Gregg's brand for the New Zealand supply of red sauce (tomato sauce and ketchup), barbecue sauce and steak sauce, and the F. Whitlock & Sons brand for the supply of Worcestershire sauce in New Zealand.
In making its decision, the commission primarily considered competition issues in the national markets for the manufacture, importation and wholesale supply of a number of table sauces to supermarkets and the food service industry.
"We believe the merger of the number one and two wholesale suppliers to supermarkets of red sauce, barbecue sauce, steak sauce and Worcestershire sauce would be likely to result in a substantial lessening of competition in each of these markets," commission chairman Dr Mark Berry said.
"However, we consider the divestment offered by Heinz Wattie's is sufficient to remedy the competitive harm the merger would cause and we have given clearance to the merger subject to the divestment undertaking."
The Wattie's operation in Hastings was the first to be established by James Wattie in 1934.
There are now two manufacturing facilities in the area.
The King St site is the original home of Wattie's operations and now employs more than 500 permanent staff and up to 800 seasonal workers.