ENDANGERED SPECIES: Some stockists have already sold out of Marmite.

New Zealand's Marmite stock is expected to run out within weeks, according to its maker Sanitarium.

Production on the Kiwi breakfast staple had to be suspended after earthquake damage to a cooling tower at the company's Christchurch factory rendered the nearby Marmite building unsafe.

Sanitarium general manager Pierre van Heerden said hopefully enough stock was in circulation to last a few weeks, but production wasn't expected to resume until midway through this year.

"The tower, which is next to the Marmite facility, suffered considerable damage in the Christchurch earthquake and has had to be deconstructed. While that is happening, workers have had to vacate the Marmite factory because it is unsafe."

He said work was happening to either identify a new building to house the Marmite factory in, or to carry out work on the tower as quickly as possible so staff could move back in, but another jar of Marmite was not expected to be made there until July.

"We are in the process of talking to food distribution centres to get an idea of how much stock is out there, but it is hard because some supermarkets will have more stock than others.

In the meantime, he recommended enjoying the spread on toast, not bread, as the heat would melt the Marmite and stretch it further.

"Some sizes have already sold out in some places. But we urge consumers not to buy huge boxes of it, as it's a Kiwi favourite and people need to be considerate of their fellow Kiwis."

The plant produces about 640,000kg of Marmite every year.

The damaged tower is attached to the Weetbix factory, and earlier this year Sanitarium had to halt manufacturing on New Zealand's favourite cereal, while they shipped production up to a smaller factory in Auckland.

Foodstuffs, which owns New World, Pak'n'Save and Four Square, confirmed their Marmite stocks were dwindling.

Spokeswoman Antoinette Shallue said distribution centres in Auckland, Wellington and the South Island all had stock, but some supermarkets across the country were already experiencing supply issues.

"It is our understanding that Sanitarium hope to resolve the supply issue by mid July, and we will be staying in close contact with them over the coming months."

Meanwhile, iPredict will be opening up betting on the rationing of Marmite - offering punters $1 for the correct guess on whether either Foodstuffs or Progressive Enterprises place restrictions on the number of jars a customer can buy before August 1.

iPredict was expecting a flurry of bets when the poll opened at 2.30pm.

iPredict Administrator Oliver Ibbetson said for the $1 to paid, rationing needed to be implemented in only a single Countdown, PAK 'n SAVE or New World supermarket, and confirmed by the relevant company, Foodstuffs or Progressive Enterprises.

Progressive Enterprises, however, may have already put paid to that bet.

The company, which owns Countdown, confirmed this afternooon they would not begin rationing the yeast spread.

Merchandise general manager Murray Johnston said they had not yet seen evidence of bulk buying, but would not be enforcing a purchase limit.

"We anticipate running out of stock of Marmite in the next two to three weeks across all our stores, and unfortunately we have no control of the situation concerning our supplier, Sanitarium."

How do you think New Zealanders should make their Marmite last until July?