The co-chair of Sony Pictures has stepped down nearly three months after a cyber attack on the company revealed embarrassing e-mails.

The hack last year led to the studio delaying the release of the film The Interview, which mocked North Korea.

Amy Pascal is going to start a new production project at the studio.

"I have spent almost my entire professional life at Sony Pictures and I am energized to be starting this new chapter based at the company I call home," said Ms Pascal in a statement.

She added that her transition to a production role had been discussed "for some time".

Since 2000, and under Ms Pascal's leadership, Sony Pictures says it has had 95 movies hit number one at the US box office.

In 2013, Ms Pascal was elected to the Board of Governors of the Academy of Motion Picture Arts and Sciences (AMPAS).

Last month, US President Barack Obama authorised fresh sanctions on North Korea as the "first aspect of our response" to the Sony hack.

The sanctions affected three North Korean entities, including a government intelligence agency and a North Korean arms dealer, the Obama administration said.

The US also imposed sanctions on 10 individuals who work for those entities or the North Korean government.

The executive order from Mr Obama is said to be "is a response to the government of North Korea's ongoing provocative, destabilizing, and repressive actions and policies, particularly its destructive and coercive cyber attack on Sony Pictures Entertainment."

"The order is not targeted at the people of North Korea, but rather is aimed at the Government of North Korea and its activities that threaten the United States and others," Mr Obama added.

North Korea has denied any involvement in the cyber attack, and has proposed a joint investigation with the US.

US sanctions against Pyongyang have been in place since the 1950s, and were tightened after three nuclear weapons tests.