"Given the importance of women in every aspect of our business, we don't feel this is a good environment in which to advertise our products right now", she said.
Over the past two days, Mercedes-Benz, Hyundai, BMW and more than a dozen other blue-chip advertisers have withdrawn spots from the show amid the scandal over sexual harassment allegations leveled at the veteran Fox News host.
The defections show that the growing scrutiny of the treatment of Fox News' female employees is beginning to have an impact on the business. Her lawsuit claims that Ailes - who O'Reilly has defended - would insist upon hello kisses before meetings and require her to bend over so he could look down her dress, reported the Associated Press. O'Reilly has said the claims had no merit but were settled to protect his children.
Slater was sacked from the network last month, and the network issued a statement saying that they "took the appropriate action in investigating and firing Ms. Slater within two weeks of this being brought to our attention".
The South Korean firm is "reallocating them (to other Fox programs) due to the recent and disturbing allegations", according to a statement to AFP.
"As the Commission may be aware, the media has recently reported on a number of claims that have been asserted against Fox News, its management, and/or its on-air personalities for unlawful discrimination, harassment, and/or retaliation, in addition to the Plaintiff's claims", the letter reads.
Representatives for Fox News and 21st Century Fox did not immediately answer questions.
At least 17 companies have announced they are ending advertising on The O'Reilly Factor. In a statement posted on his website April 1, O'Reilly wrote that his fame has made him susceptible to lawsuits, but that no complaints have ever been filed against him internally to the company's human resources department, even anonymously.
"The O'Reilly Factor" is the most widely viewed United States cable news show with an average of 3.98 million viewers in early 2017, according to Adweek.
Walsh alleged that O'Reilly asked to get dinner with her in Los Angeles in 2013, where he said he would recommend her for a paid contributor role at Fox.
O'Reilly is Fox News' top revenue producer, according to research firm Kantar Media, bringing in over $178 million in ad dollars in 2015 and $118.6 million in the first nine months of 2016.
"The O'Reilly Factor" is now the highest-rated show on cable news, averaging around 4 million viewers per night. Reports estimate that up to 22 advertisers have left the show.
Money reached out to "more than 20 companies" that also advertise on The O'Reilly Factor, and while several did respond to the queries, none of them seemed willing to actually distance themselves from O'Reilly's increasingly toxic brand.