Dutch food group Vion, which owns Hall's of Broxburn in West Lothian, said neither of the offers "constitutes a viable and sustainable alternative" to its proposed closure.
The factory, which produces the world's biggest-selling haggis, is currently making losses of £79,000 a day.
Vion UK chairman Peter Barr said: "In neither instance were we assured that either offer provided a guarantee of ongoing employment for the workforce, in spite of the fact that Vion was prepared to offer substantial financial assistance to support the acquisition.
"This is a very sad day for the company but, unfortunately, the plant continues to suffer unsustainable losses of £79,000 a day.
"Consequently, it is with great regret that we can confirm that it is our intention to proceed with plans for a phased closure of the plant."
Some areas of the plant will cease production later this month, with full closure expected to take place by February next year.
Discussions have already been held with employees and union representatives on redundancy terms, the company said.
The Scottish Government outlined what it called a "comp-rehensive recovery plan" to support the local economy following confirmation of the shutdown.
A taskforce set up in July when the closure plan emerged will focus on finding alternative jobs for workers.
Finance Secretary John Swinney said: "We are deeply disappointed that Vion have been unable to accept either of these bids and have now confirmed the decision to close Hall's of Broxburn.
"Teams are already in place working to support staff facing redundancy."
Mr Swinney added: "The work of the Hall's of Broxburn taskforce will continue.
"The Scottish Govern-ment, its agencies and West Lothian Council will work together to find alternative employment for all those affected by this decision and to develop opportunities to enhance the wider West Lothian economy.
"I have con-firmed to West Lothian Council that the Scottish Government will partner in the economic regeneration of Brox-burn and officials are developing plans which we will bring to the taskforce at the end of October.
"These plans will help to mitigate the impact of this closure on West Lothian as a whole."