The Women's Prize for Fiction - formerly known as the Orange Prize - is to be funded privately next year while the search continues for a new sponsor.
Cherie Blair is among the donors who have come forward.
Entrepreneur Martha Lane Fox and author Joanna Trollope are also helping to fund the £30,000 prize.
Mobile company Orange announced in May it was ending its 17-year sponsorship of the prize, which recognises English language fiction written by women.
Kate Mosse, the prize's co-founder, said she had been "overwhelmed with interest" from potential sponsors.
Next year's winner is due to be announced on 5 June at London's Royal Festival Hall.
An announcement said the prize would be privately funded while "headline sponsorship negotiations for 2014 and beyond are concluded".
"We were overwhelmed with interest from potential headline sponsors," said Kate Mosse, chair of the Women's Prize for Fiction board.
"However, it became clear sponsorship budgets for next year were already committed, so we took the decision to privately fund the Prize for 2013."
Funding has been provided in the form of gifts from companies and individual donors, some of whom wish to remain anonymous.
The judges for the prize in 2013 will be actor Miranda Richardson (chair); Razia Iqbal, BBC journalist and broadcaster; Rachel Johnson, author, editor and journalist; JoJo Moyes, author; and Natasha Walter, feminist writer and human rights activist.
"This is a new departure for me and I am honoured to be working with judges who combine fine minds with, I suspect, great good humour," Richardson said.
When Orange announced it was ending its sponsorship - to focus its brand on the film industry - Mosse wrote an open letter inviting potential sponsors to get in contact.
In July she told the BBC that 18 companies had come forward and that "serious conversations" were taking place, but nothing had been finalised.
For 2013, the prize will also enter a new partnership with Google "on a number of new initiatives which will support the prize's ambition of reaching a wider, international audience" via platforms such as Google+ and YouTube.
This year debut US novelist Madeline Miller won the award with The Song of Achilles, a story of same-sex romance set in the Greek age of heroes.
Previous winners include Tea Obreht for The Tiger's Wife (2011), Barbara Kingsolver for The Lacuna (2010) and Lionel Shriver for We Need to Talk About Kevin (2005).
The prize winner receives a cheque for £30,000 and a limited edition bronze figurine known as a "Bessie", created and donated by the artist Grizel Niven. Both are anonymously endowed.