Simon Property Group, the owner of the King of Prussia Mall, is embarking on a new e-commerce venture, writes Lauren Thomas for CNBC.

The biggest mall owner in the country is partnering with Rue Gilt Groupe, the parent company of online shopping site Rue La La, to start a new kind of website for people searching for deals online.

Since March, Simon has been testing the ShopPremiumOutlets.com website, building on its business of premium outlet centers that includes dozens of locations nationwide as well as several overseas. The mall owner has been working with several retailers at those centers to test out selling their merchandise together on the site.

The goal is to give shoppers the chance to buy discounted items online if they do not have a brick-and-mortar outlet center close by.

Already, Simon has signed on more than 2,000 designers with around 300,000 products on offer, including the brands Aeropostale, Nautica, and Under Armour.

Simon will contribute $280 million towards the venture and will also market the new business using a portion of its annual marketing budget that is over $100 million.

Read more about the new e-commerce platform at the CNBC by clicking here.