FIS president Stephanie Ferris, who was set to take on the CEO role in January, is now taking up the job with immediate effect.

Gary Norcross, a 34-year FIS veteran who has been CEO since 2015, leaves the company and his position on the board.

Norcross had been set to take on the role of executive chairman but FIS is now making Jeffrey Goldstein, currently lead independent director, independent chairman.

In addition, the company is adding a board member in the shape of Mark Ernst, who had been EVP and chief operating officer at FIS rival Fiserv.

According to Reuters, the changes come after investor DE Shaw pushed FIS to "assess its business configuration and structure".

FIS has seen its share price fall by a third over the last year.

Ferris will now lead a review with a focus on "identifying and optimising incremental revenue generation, margin improvement and cost reduction opportunities.

"The review will also evaluate FIS’ business structures and portfolio of assets to ensure optimal configuration and deliver the greatest results for FIS’ clients and shareholders."

Both DE Shaw and another investor, Jana Partners, welcomed the changes.

Last month, Bloomberg reported that Ferris had already planned to axe several thousand jobs in an effort to cut hundreds of millions of dollars in costs.

Says Ferris now: "We are taking a hard look at every aspect of our company to define areas for change and develop specific action and improvement plans."