LONDON — Kraft Foods Inc. must announce a firm intention to make an offer for Cadbury P.L.C., or instead state it does not intend to make an offer, by Nov. 9, according to a ruling made Sept. 30 by The Panel on Takeovers and Mergers, a London-based independent body that regulates takeover bids and other merger transactions for companies with registered offices in the United Kingdom.

Both Kraft Foods, Northfield, Ill., and Cadbury, London, have accepted the ruling, according to The Panel.

"We’ve noted the decision and understand the implications," said Lisa Gibbons, associate director, corporate external communications, for Kraft Foods.

Kraft Foods on Sept. 7 disclosed it was pursuing a $16.7 billion takeover of Cadbury. Adding Cadbury would create a business with $50 billion in revenues that would be a "global powerhouse in snacks, confectionery and quick meals," Kraft said.

The board of Cadbury rejected the bid on the grounds that it made no strategic or financial sense for Cadbury and undervalued the company. Kraft said it would continue to pursue the acquisition.

Roger Carr, chairman of Cadbury, said on Sept. 30 he welcomed the deadline decision from The Panel.

"Cadbury has a strong position in the global confectionery market, and the board is confident in Cadbury’s standalone pure play strategy and growth prospects," he said. "We have made our position on Kraft’s proposal very clear, and we welcome The Panel’s decision today in the interests of obtaining clarity and certainty for our shareholders and employees at the earliest opportunity."