Image copyright AP Image caption Jennifer Lawrence said she was excited to write the essay for Lena Dunham who she called a "genius"

Jennifer Lawrence has written an essay expressing her anger at getting paid less than her male co-stars.

In the article on Lena Dunham's site Lenny, she said: "I'm over trying to find the 'adorable' way to state my opinion and still be likable!"

She said she only found how much less she was being paid when emails from Sony Pictures were hacked last year.

"I didn't get mad at Sony. I got mad at myself. I failed as a negotiator because I gave up early," she said.

Sony's internal computer system was hacked in November. The leaked emails started making headlines soon afterwards.

One of the biggest stories involved emails from Sony boss Amy Pascal that revealed Jennifer Lawrence and Amy Adams were paid much less than their American Hustle co-stars.

In her essay, The Hunger Games actress went into more detail about her reasons for not fighting for more money.

"I would be lying if I didn't say there was an element of wanting to be liked that influenced my decision to close the deal without a real fight. I didn't want to seem 'difficult' or 'spoiled'.

"At the time, that seemed like a fine idea, until I saw the payroll on the Internet and realised every man I was working with definitely didn't worry about being 'difficult' or 'spoiled'."

Image copyright AP/Sony Pictures Image caption Jennifer Lawrence earned an Oscar nomination for her role in American Hustle as did Amy Adams, Christian Bale and Jeremy Renner

She also opened up about how she is treated as a woman in Hollywood.

"All I hear and see all day are men speaking their opinions, and I give mine in the same exact manner, and you would have thought I had said something offensive," she said.

"I'm over trying to find the "adorable" way to state my opinion and still be likable!"

Last week, Meryl Streep - one of Hollywood's most successful actors - spoke out about sexism in the film industry, saying that even she receives less pay than male co-stars.

Streep was talking to the BBC ahead of the London premiere of her film, Suffragette, about the militant campaign in support of women's voting rights in the UK.

Suffragette opened the London Film Festival which is also held a global symposium on gender in the media with Oscar-winning actress Geena Davis.

At the symposium Davis called for more women on screen and more challenging female roles in TV and film.

"We are unwittingly training generation after generation to see men and women as unequal," said Davis who was speaking on gender in media in London.

"Surely in the 21st century we should be showing kids that boys and girls should be sharing the sandbox equally?"

Earlier this year Davis launched a Hollywood film festival to both highlight the problem and showcase the work of female talent in the industry.

In one hacked Sony email, actress and director Angelina Jolie was referred to as a "spoiled brat".

Lawrence ended her post by saying that, after her experience, she wasn't surprised.

"For some reason, I just can't picture someone saying that about a man."