The Sex And The City star is ditching her contract with design house Halston, which would have entitled her to nearly $10m over the next three-and-a-half years, according to the New York Post.
Parker, who had been designing a lower-price line called Halston Heritage, has now reportedly agreed to accept $3m for her ownership stake in the failing firm, as well as an exit from the remainder of her contract.
'She was tired of all the conflict,' a source told the New York Post.
'Sarah felt that she has the opportunity to do a lot more with herself, and make a lot more money in the process, if she goes elsewhere.'
The actress is not alone in jumping ship from Halston, according to the US newspaper.
Hollywood mogul Harvey Weinstein is also reportedly selling his stake, which had approached 10 per cent, for between $1m and $1.5m.
Fashion sources have claimed that Halston has been rocked this year by arguments between Weinstein and executives at Hilco, a Chicago-based liquidation firm that took control of Halston in 2007 in a $25m buyout.
'There have been a lot of screaming matches,' a Halston insider told the New York Post. 'They really couldn't agree on too much – the management team, expenses, the company's structure.'
Chief financial officer Jeff Green declined to comment.