On-demand delivery giant Meituan on Monday reported better-than-expected revenue in the first quarter as it sought to maintain its dominance in a fiercely competitive mainland market.

Revenue for the first three months reached 86.6 billion yuan (US$12.1 billion), up 18.1 percent year on year, beating analysts forecasts of 85.4 billion yuan.

The Beijing-based firm said in a statement that the gains were partially driven by its robust instant delivery business, which refers to deliveries of not only food but also a slew of everyday consumer items, often within an hour.

Its "retail plus technology" expansion strategy, too, helped drive the growth, with the firm saying it has integrated artificial intelligence technology into work processes and across its range of consumer services. Meituan earlier announced plans to build its own AI model.

The gains also came as the mainland saw a heated "delivery war" over the past few months when new industry players, including JD.com as well as Taobao-backed Flash Sale, entered the market to challenge Meituan's dominance at home.

The latest rivalry between the delivery platforms prompted regulatory officials to intervene in the market to call for fair and lawful competition.

Meituan, which has a 65 to 70 percent market share on the mainland, has recently ramped up efforts to expand its presence in Hong Kong, the Middle East and elsewhere.

Most recently, the company said it was planning to spend US$1 billion to take its Keeta food delivery app to Brazil.