Singapore's Sea Ltd SE.N reported a sharp rise in quarterly operating expenses on Tuesday, amid heavy spending to fend off competition in the Southeast Asian ecommerce industry, sending its U.S.-listed shares down 15% premarket.

The costs reflect the company's efforts to attract consumers to its platform through incentives such as discounts, offers and loyalty benefits, while rivals such as TikTok Shop also expand.

Sea is also investing in its logistics and delivery services to capture more market share in key markets such as Singapore, Indonesia and Thailand.

Total operating expenses grew over 28% to $2.43 billion in the fourth quarter from a year ago.

The company reported quarterly revenue of $6.85 billion, surpassing analysts' average estimate of $6.45 billion, according to data compiled by LSEG.