Suncor Energy Inc said on Friday its chief executive, Mark Little, has stepped down after a string of fatalities at Canada's third-largest oil producer.

Little was also stepping down as president and resigning from the board effective immediately, the Calgary, Alberta-based company said in a statement.

Kris Smith, the company's executive vice president of downstream will replace Little as interim CEO, while the board launches a search for a permanent replacement.

Little's resignation comes a day after a worker was killed at Suncor's oil sands base plant in northern Alberta. It was the second fatality at a Suncor site this year and the thirteenth since 2014.

"Suncor is committed to achieving safety and operational excellence across our business, and we must acknowledge where we have fallen short and recognize the critical need for change," board chair Michael Wilson said in a statement.

Little, who became Suncor CEO in 2019 after serving as chief operating officer, has been under pressure to fix safety and operational issues. He told investors in February he took full responsibility for fatalities on Suncor sites and vowed to improve operations.

In April U.S.-based activist investment firm Elliot Management disclosed a 3.4% stake in Suncor and urged the company to install new board directors, overhaul management and begin a strategic review, noting that Suncor's share price was lagging its peers.

Elliot's public criticism increased scrutiny of Little's performance as chief executive.

In 2020 Suncor was overtaken by rival Canadian Natural Resources Ltd as Canada's most valuable energy company.

In addition to the fatalities, the company disappointed investors by making a major dividend cut in 2020, repeatedly missing production guidance and running into operational issues at its new Fort Hills oil sands mine that have delayed the project reaching full production capacity.

(Reporting by Abinaya Vijayaraghavan in Bengaluru; Editing by Sandra Maler and William Mallard)