Top retailer Walmart has posted a rise in sales and earnings, bolsted by its fast-growing advertising business.

Walmart reported a 5.3% rise in revenues at constant currency in the fourth quarter, bringing the total for the last financial year to $684bn – up 5.6%. Operating income was up by 9.4% in the quarter and 9.7% to $29.7bn for the year.

Walmart’s advertising business was a star performer. Last year its global advertising division was ahead 27% to reach sales of $4.4bn. In the fourth quarter it grew 29%, including 24% at Walmart Connect in the US.

Retail media is becoming increasingly important for retailers in the UK, such as Tesco, and the scale of business which Walmart has built up illustrates how it can become a significant revenue stream.

In the fourth quarter, Walmart benefited from other factors such as growth in membership income and “improved economics in ecommerce. The retailer’s global ecommerce sales rose by 16%, led by pick-up & delivery fulfilled in store” and its US marketplace.

Walmart chief executive Doug McMillon said: “Our team finished the year with another quarter of strong results. We have momentum driven by our low prices, a growing assortment, and an ecommerce business driven by faster delivery times.

“We’re gaining market share, our top line is healthy, and we’re in great shape with inventory. We’ll stay focused on growth, improving operating margins, and strengthening ROI as we invest to serve our customers and members even better.”