(Corrects paragraph 7 to say absorption of costs is going to wane, not weigh)

By Granth Vanaik and Waylon Cunningham

(Reuters) - DoorDash ( DASH ) projected second-quarter core profit below expectations on Wednesday despite beating first-quarter revenue estimates, indicating that higher costs were offseting some of its gains from rising groceries and food orders.

Shares of the company were down 12% in extended trading.

The online delivery firm has been forced to increase minimum pay for its delivery workers after New York City and Seattle came up with new regulations.

"When I look at the business from Q4 to Q1, costs did go up," said CFO Ravi Inukonda in an interview with Reuters, adding that the company passed on some fees to consumers.

DoorDash ( DASH ) expects adjusted earnings before tax, interest, depreciation, and amortization between $325 million and $425 million, the mid-point of which is below an estimate of about $393.8 million, according to LSEG data.

The company said the new regulation made its platform "less accessible and less flexible" for the people who used to generate income in those cities and reduced total orders by less than 1% in the quarter.

"The absorption of cost is going to wane as we go through the rest of the year," Inukonda said.

GAINED MORE MARKET SHARE IN THE QUARTER

DoorDash ( DASH ) has been trying to branch out of its core food delivery business into newer verticals such as grocery, retail and alcohol in a bid to attract more customers to its platform.

Its total orders rose 21%, to 620 million in the quarter.

Inukonda said DoorDash ( DASH ) has gained market share in "virtually all lines of business" across the 30 countries it operates in.

He said the grocery business was the fast-growing aspect of the business, with grocery orders doubling from last year.

DoorDash's ( DASH ) gross order value - a key industry metric showing total value of all app orders and subscription fees - was up by 21%, to $19.24 billion in the first quarter.

The company expects second-quarter GOV to be between $19 billion and $19.4 billion.

Its first-quarter revenue rose over 23%, to $2.51 billion, compared to expectations of about $2.45 billion.

Net loss narrowed to $23 million, or 6 cents per share, compared to $161 million, or 41 cents, a year earlier.

(This story has been corrected to clarify that the absorption of costs is going to wane, not weigh, in paragraph 7