March 24 (Reuters) - FedEx ( FDX ) said on Tuesday it had launched a same-day delivery service with last-mile delivery software company OneRail, as retailers and logistics firms race to speed up order fulfillment.

The service, called FedEx SameDay Local, lets customers choose narrower delivery windows, including two-hour and end-of-day options. FedEx ( FDX ) said it links customers to a national network of more than 1,000 delivery providers through a system that matches orders with the nearest vehicle and driver.

The move comes as companies across the sector invest in faster fulfillment and stronger last-mile networks to meet rising customer demand for quicker and more flexible delivery.

Earlier this month, Amazon ( AMZN ) expanded its fast-delivery offerings by rolling out one-hour and three-hour shipping in markets across the U.S., amid intensifying competition from rivals including Walmart ( WMT ) and Target ( TGT ), which are also expanding same- and next-day delivery.

FedEx ( FDX ) said the service broadens its ability to support customers across the delivery chain, from long-haul transportation to local fulfillment.