Seven has strongly rejected claims of other inappropriate relationships between Worner and current or former female staff.
"Allegations made in her statement which name other employees are rejected totally, including any allegation that other current or former employees have been paid off," the company said.
In a statement issued on Monday night, Seven condemned the inappropriate sexual relationship with Harrison, 35, as "completely unacceptable" and "deeply regrettable".
Worner apologised for the affair, which began before his appointment as chief executive. "This relationship finished some years ago and I apologised at the time, and am still trying to make amends," he said in the statement.
"I am obviously filled with the deepest regret and shame.
"My focus is to continue to work through this in private and minimise the distress to my family. They are the most important people in the world to me and I will continue to fight to repair the damage I've caused."
In the statement issued by the network, the board declared Worner would continue as chief executive, despite the battering the share price took yesterday.
Former executive assistant Harrison revealed explicit text messages she says were sent to her by Worner, amid claims she was paid off to the tune of $100,000 when leaving the company.
The Seven West Media board held a crisis meeting yesterday in response to Harrison's shocking statement, including sexually explicit texts and details of the "consensual sexual relationship".
Harrison makes the unsubstantiated claim the couple engaged in cocaine-fuelled sexual encounters, some of which took place at work events.
Seven's statement did not address claims of alleged drug use, instead saying Harrison's statement was full of "wideranging inaccuracies".
Amid a "complex" and "frustrating" severance negotiation following Harrison's redundancy in November 2014, the now unemployed woman shared details of her alleged affair with the married father-of-four and the "entrenched sexist culture" she claims rewarded male executives for "behaving badly" within the company.
Seven fired back, saying a confidential settlement deed was entered into more than two years ago with Harrison, who was represented at the time by Harmers Lawyers, who Seven understands have since ceased acting on her behalf. The settlement deed was approved by the relevant board committee of Seven and continues to be binding.
Seven says in the statement it agrees that the inappropriate consensual sexual relationship made public by Harrison is deeply regrettable.
Seven chairman Kerry Stokes has always made clear to Worner that the alleged conduct, even though a personal matter, was completely unacceptable, according to the statement.
"Separately, Tim Worner apologised at the time and now, for the inappropriate consensual relationship with Ms Harrison, that commenced prior to his appointment as chief executive, and has been working with the board and executive to ensure this improper behaviour is not a part of Seven's culture," the statement read.
Harrison said she received $100,000 as part of a confidentially settlement in August 2014, however was made redundant in a second agreement in November 2014, in which the company offered to pay her $350,000. Harrison said she was never paid the agreed amount.
Her redundancy coincided with an investigation into Harrison's alleged misuse of corporate credit cards and personal expenses.
Seven rejected that its investigation was a "vindictive reaction" to the relationship.
The company said the audit arose from "standard expense reconciliation inquiries" before management became aware of the affair.
Describing Worner as a "regular churchgoer who lives at Manly with his family", Harrison's statement claimed the Seven boss began sending her explicit text messages after a 2012 meeting.
The affair, which Harrison claims spanned two years, began with flirting after a meeting.
"We started flirting and soon after Tim began texting and emailing me for sex," Harrison said.
"I knew he was married. It was never about love. It was about sex and power. He likes having a bit on the side. I found our relationship, if you'd call it that, thrilling to begin with."
She claimed Worner's "sexual proclivities and eagerness" were laid bare in hundreds of texts exchanged between the pair, which Harrison said she destroyed "at Seven's direction".
Harrison alleged the pair's encounters continued, including at Seven-sponsored events such as the Australian Open, until mid-2014 when Harrison claimed she became depressed and began having panic attacks.
Since making her grievances public, Harrison has challenged Seven to "play out their war of law against me in public now".
Seven says both Seven and Harrison agreed to confidentiality and "mutual non-disparagement", without admissions of wrongdoing.
The payment, agreed to be made to the former employee in instalments, took into account Harrison's solicitors' strong assertions regarding her needs and fragile emotional stability and were designed to enable Harrison to move on with her life, Seven said.
Seven says it is entitled to withhold payment for noncompliance with the settlement deed.
Harrison's complaint in the Australian Human Rights Commission failed to progress.
