NEW YORK (Reuters) -Walmart said on Thursday it is closing a fulfillment center that services online orders for its warehouse club chain Sam's Club in Fort Worth, Texas, and sources familiar with the matter said the move could result in job losses.

Walmart confirmed the closure to Reuters but said it could not estimate the number of possible job losses until employees make their decisions on relocation.

"We're continuously evolving our fulfillment network to improve service for our customers and members as their needs change," the retailer said in a statement.

"We are relocating operations ... to other facilities within our fulfillment network," it added.

Volumes that were handled at the fulfillment center known as DFW4 will be relocated to a high-tech fulfillment center in Lancaster, Texas, and three other Dallas-area facilities, a spokesperson said.

Walmart has significantly ramped up investments in its e-commerce operations to accelerate delivery times and better compete with Amazon.com. In the first quarter, these efforts paid off as the retailer reported its first-ever profit from its online business.

Sales at Sam's Club - Walmart's membership-based warehouse chain - surged 27% during the same period. The company also noted that more than 50% of its members now use digital transactions in some form with Sam's Club.

The DFW4 facility's relocation will be completed by summer, the spokesperson said, adding that the retailer has roles for all affected people, if they choose to continue with Walmart.

Sources familiar with the DFW4 facility, including one who applied for a position there in February, said the center employed hundreds of workers. The hourly pay for a freight handler position at the facility showed a wage range between $21.60 and $25.10 per hour, according to Walmart's career portal.

The retailer said it would help employees obtain jobs at surrounding Walmart facilities, including stores. It said it will also offer a $7,500 transfer bonus and relocation benefits to those who choose to move to any of its Walmart high-tech fulfillment centers in the country.