Feb 12 (Reuters) - Instacart forecast current-quarter gross transaction value and core profit above expectations and beat fourth-quarter estimates on Thursday, helped by strong demand for essentials on its online delivery platform and rising advertising revenue.

Shares of Instacart were up 15.8% in extended trading.

The company, formally known as Maplebear, logged strong order growth as inflation-weary consumers sought cheaper produce, dairy and pantry staples while leaning on the convenience of rapid delivery options. The strategy has helped Instacart retain budget-conscious shoppers looking to stretch their spending.

The delivery firm's advertising arm also enjoyed growth, closing the year with about 9,000 active brands, up 2,000 from a year earlier, helping push the segment's revenue above $1 billion in 2025.

For the current quarter, Instacart expects GTV - a key metric that shows the value of products sold based on prices shown on Instacart - between $10.13 billion and $10.28 billion, topping analysts' average estimate of $9.95 billion according to LSEG data. The forecast implies 11% to 13% year-on-year growth.

It sees adjusted earnings before tax, depreciation, and amortization for the current quarter between $280 million and $290 million, compared with analysts' expectations of $279.5 million.

For the quarter ended December 31, GTV rose 14% to $9.85 billion, beating estimates of $9.5 billion. Adjusted core profit was $303 million, above estimates of $292.2 million.

Advertising and other revenue increased 10% to $294 million, in line with year‑ago growth. Orders climbed 16%, outpacing the 11% growth a year earlier

The company, which launched an app on OpenAI's ChatGPT in December, is nevertheless bracing for tougher competition. Amazon is planning a delivery service targeting below-30-minute drop‑offs, and Kroger announced an expansion of its partnership with Uber Eats in January, both of which could chip away at Instacart's market share.