Amazon.com is reportedly experimenting with a new delivery service intended to make more products available for free two-day delivery.

According to Bloomberg's sources, Amazon.com's plan will push the online retailer deeper into functions handled by longtime partners United Parcel Service and FedEx.

The service began two years ago in India, and Amazon has been slowly marketing it to U.S. merchants in preparation for a national expansion, said the report. The service began on a trial basis this year in West Coast states with a broader rollout planned in 2018, the report added.

Amazon will oversee pickup of packages from warehouses of third-party merchants selling goods on Amazon.com and their delivery to customers' homes -- work that is now often handled by UPS and FedEx.

Amazon declined to comment.