Members will be able to locate businesses participating in the scheme by clicking on the 'Find Rewards in your area' link on the Nectar web site.
This will tell them where they can find outlets such as Argos, Blockbusters, Cannons health clubs and Cafe Uno, where they will be able to earn more points or redeem those they have already earned.
Jeff Kelisky, Multimap's chief executive officer, commented: "The mapping and local information services we provide our customers offer a significant enhancement to the end-user's experience online."
The deal aims to increase use of the web site and, ultimately, the loyalty programme.
Simon Hawkes, chief operating officer at Loyalty Management UK, added: "Multimap's flexible technology, which was deployed quickly and smoothly, means that Nectar Collectors can now find their nearest Rewards suppliers and sponsors in a matter of seconds. This is great for collectors and for our rewards partners, who will see traffic through their doors increase considerably."
Multimap is one of the 10-most visited sites in the UK, claiming some 90 million page impressions a month.