The American food giant has until December 7 to publish its offer document, but the sources said it was expected on Friday, and would be at the same cash and shares terms Kraft first unveiled to the British confectioner back in early September.
Kraft is ready to go so sees no reason to wait until Monday, and is expected to publish late morning on Friday, said one source with knowledge of the situation.
Cadbury rejected Kraft's bid, forcing the U.S. group to turn hostile in early November and prepare to go directly to Cadbury shareholders in its aim to create the world's largest confectionery group.
The current terms of 300 pence in cash and 0.2589 new Kraft shares for each Cadbury share value the British group at 715 pence, compared Cadbury's closing share price in London of 800p.
They see no reason to change the terms as Kraft will have 46 days to consider a higher bid, said another source.
If Kraft does post the offer document on Friday that will become day 1 in a 60-day timetable under UK takeover rules. It will have until day 46, the middle of January, to raise its bid for the Dairy Milk chocolate maker. Cadbury will have until day 14 to publish its defense document.
Cadbury shares have been boosted by hopes of a higher Kraft offer and potential bids from rivals such as Italy's Ferrero and Hershey Co
The deadline is Monday. I can assure you we'll meet that deadline, said a Kraft spokeswoman.
Cadbury declined to comment.
(Reporting by David Jones, additional reporting by Brad Dorfman, editing by Will Waterman)