• Walmart has hired John Rainey, PayPal's chief financial officer, as its new CFO.
• He will take the reins from longtime Walmart CFO Brett Biggs, who announced in November that he would be leaving the company.
• Rainey is joining Walmart as the big-box retailer chases new streams of revenue. Among them, the company wants to expand its third-party marketplace and ramp up its advertising business..

Walmart said Tuesday it had tapped PayPal executive John Rainey as its new chief financial officer.

Rainey currently holds the same post at the financial technology company and will step in as CFO at Walmart on June 6. He will take the reins from longtime CFO Brett Biggs, who announced in November that he would step down.

Walmart CEO Doug McMillon said in a news release that Rainey "has a proven track record of leading change at scale in customer service organizations innovating in their fields.

"I'm confident that John's mix of financial and digital acumen, coupled with his experience leading finance in complex, highly competitive industries, will help us deliver for our customers and shareholders as we continue to transform our company," McMillon said.

Rainey is joining Walmart as the big-box retailer chases new streams of revenue. Among them, the company wants to expand its third-party marketplace and ramp up its advertising business.

Walmart also has invested in new areas. It created and backed a fintech startup that's led by former Goldman Sachs bankers. Biggs, the retailer's outgoing CFO, sits on the startup's board.

Biggs will step down from his role at Walmart in early June, but stay on as an advisor through Jan. 31 to support the transition.

Prior to joining PayPal, Rainey was CFO at United Airlines. He began his career at Ernst & Young.