The petrol and convenience giant has agreed to use Nisa until the new year as a temporary solution and will then review its options.
"We have switched supplier for the Christmas period, with a very smooth transition and no impact to sales or customer service," said a BP spokesman. "We are in the process of reviewing all available supply options going into the new year and see this as a great opportunity to further evolve our offer and reduce our supply chain costs."
Nisa group sales director Andrew Mouse said: "This is a short-term deal but is one that is mutually beneficial for both companies. Nisa-Today's and BP are both delighted with the arrangement."
BP has yet to decide how to rebrand up to 100 mini off-licences within its forecourts that carry Threshers-branded alcohol.
The spokesman said BP had "no plans to buy the Threshers brand" and it is understood it will be legally required to take down the imagery early in the new year.
Meanwhile, Wickham Vineyards has become the second-largest buyer of FQR outlets to date after snapping up 14 stores in Hampshire.
The stores will be used to sell some of the 400,000 bottles of wine produced by the company each year.It has yet to decide from where it will source the rest of the alcohol or tobacco it plans to sell and what it will call the stores.
"It's a very exciting time for our business," said Wickham director Wilhelm Mead.
KPMG had previously aimed to sell hundreds of the former FQR stores to bulk-bidders by mid-December, but had sold only 83 sites as The Grocer went to press. More than 1,000 of the 1,200 outlets have been passed on to property agent Christie & Co to sell individually.