As delivery-firm Shipt rolls out same-day delivery from its new owner, Target, there's at least one retailer from which it is no longer making dispatches: Walmart.

To be fair, there never was an official partnership between Shipt and Walmart. And Oklahoma City was the only market where Shipt delivered groceries from Walmart stores.

When it launched delivery in Oklahoma City last summer, there was a disclaimer at the end of Shipt's press release that noted: "Shipt sources groceries from local Walmart stores, however, the company is not endorsed by or affiliated with Walmart."

And Walmart set the record straight then, too. "Shipt included our brand in its recent press release without our knowledge," a Walmart spokeswoman told the Oklahoman last year.

While a bit unusual, this arrangement is not unheard of. As a host of delivery firms have proliferated in recent years, they don't always have an explicit relationship with the retailers or restaurants from which they deliver items to customers.

In any case, as Shipt launched delivery from Target stores in Oklahoma City this week, it ended its deliveries from Walmart, which of course is one of its biggest rivals. A Target spokeswoman confirmed the development, but didn't comment further on it.

Target bought Shipt late last year and plans to leverage it to roll out same-day delivery from most of its markets this year as it tries to fend off Amazon. It will launch the service in the Twin Cities on March 1, the first new market Shipt has expanded to since the $550-million acquisition.

Target executives have said they want to keep other retailers on the Shipt marketplace to make the $99-a-year service attractive to consumers and more cost effective to run. Some of the other retailers it delivers from include Kroger, Meijer and Publix.