May 8 (Reuters) - Instacart forecast its second-quarter gross transaction value (GTV) and core profit above estimates on Wednesday, helped by a surge in grocery orders as well as higher fees for the advertisements it showcases on its grocery delivery platform.

The San Francisco-based firm, formally known as Maplebear, also said that former Uber executive Emily Reuter would succeed Nick Giovanni as its new finance chief, effective immediately.

The company expects current-quarter adjusted earnings before interest, taxes, depreciation and amortization (EBITDA) between $180 million and $190 million, midpoint of which is above estimates of about $168.8 million, according to LSEG data.

With Instacart's pandemic-driven boom now relatively stabilizing, it has been relying more on selling advertisement spaces, while forging newer partnerships with retailers to attract more customers to its platform.

On Tuesday, it announced a partnership with Uber Eats for restaurant delivery services, challenging rival DoorDash's dominance. Analysts expect the move will bolster Instacart's platform engagement.

For the second-quarter, the company expects GTV, a key metric showing value of products sold based on prices shown on Instacart, to grow between $8 billion and $8.2 billion, compared with expectations of $8.03 billion.

Total orders rose 9% to 72.8 million in the quarter ended March 31, with more people opting to order in during the inclement weather conditions across the U.S. earlier in the year.

Instacart's advertisement revenues climbed 9% year-over-year in the first-quarter, sequentially improving from the previous quarter.

Total revenues rose 8% to $820 million, beating LSEG estimate of $793.4 million. However, its transaction revenues represented only 7.2% of GTV in the quarter, compared to 7.5% a year ago, as it offered more incentives to its customers on the platform.

(Reporting by Granth Vanaik in Bengaluru; Editing by Tasim Zahid)