Kraft Foods Inc chief Irene Rosenfeld refused to sweeten her $16.2 billion offer for candy maker Cadbury Plc and took the bid directly to shareholders on Monday, setting the stage for a takeover battle that could last up to three months.

North American food giant Kraft repeated on Monday the cash and shares terms of its original offer, which Cadbury rejected two months ago, and formalized the bid to meet a UK Takeover Panel deadline. The bid is now worth about 5 percent less after a fall in Kraft shares.

Cadbury lost no time rejecting the hostile bid as a derisory offer, as Chairman Roger Carr termed it. Cadbury investors also said they would not countenance the offer without a substantial sweetener, to at least 800 pence per share from the current deal value of 709 pence per share.

They need to raise the bid from here to be successful and they don't seem willing to do that, one top 10 investor in Cadbury told Reuters. If there is 8 pounds plus on the table, it is going to be difficult for Cadbury shareholders to walk away from that.

A source familiar with the situation said this was not likely to be the final offer from Kraft, which was committed to making a case to shareholders after having given up on an endorsed offer from Cadbury's board.

This just starts a new clock ticking, the source said, adding that Kraft had made no effort to hold talks with Cadbury in recent weeks.

Rosenfeld has repeatedly insisted she will not overpay for Cadbury and has a history of sticking to her guns for Kraft. Cadbury's Chief Executive Todd Stitzer has said a link-up with Kraft made no strategic sense and that it has a strong future as an independent candy maker.

Cadbury is the world's second-largest confectionery group and the maker of Dairy Milk chocolate. Kraft is No. 5, with Toblerone, Cote D'Or, Terry's and Suchard, in addition to food brands such as Velveeta cheese and Maxwell House coffee. Combined, they would edge out privately owned Mars-Wrigley from the global No. 1 confectionery spot.

A CADBURY VALENTINE?

Kraft now has 28 days to post its official offer document to Cadbury shareholders, which will then trigger the 60-day bid timetable under British takeover rules.

That would mean Kraft would know if it has won over Cadbury shareholders shortly before Valentine's Day.

Cadbury appeals to Kraft because confections are a higher margin, faster growth business than some of Kraft's packaged food lines such as cheese. Cadbury would also help expand Kraft's business into faster-growing markets such as India.

Kraft's offer does not come remotely close to reflecting the true value of our company and involves the unattractive prospect of the absorption of Cadbury into a low-growth conglomerate business model, Cadbury's Carr said.

Kraft's deal proposal valued Cadbury shares at 717 pence based on the closing price of Kraft's shares on Friday, but was already down to 709 pence based on Kraft's trading on Monday. When disclosed on September 7, the bid was at 745 pence per share.

Kraft also said on Monday that it secured a $9.2 billion bridge loan to help finance its bid for Cadbury, giving it room to raise the cash portion of the offer.

Kraft shares closed 0.9 percent lower at $26.53. Cadbury's shares fell sharply to 739p after the unchanged bid terms were announced, but edged back up 0.4 percent to close at 761p.

NO WHITE KNIGHT MOVES

In large part, Kraft's move showed it was betting that no counter-bidder would emerge for Cadbury after weeks of puncturing investor hopes for a much sweeter bid.

They've got some negotiating power here and they are leveraging it pretty smartly, said Edward Jones analyst Matt Arnold.

Potential suitors Hershey Co , Nestle SA and PepsiCo Inc

all have reasons holding them back.

Pepsi, which owns snack-maker Frito-Lay, is buying its two largest bottlers and may have little appetite for a new deal.

Nestle has said it plans no big acquisitions. Hershey has been interested in Cadbury, but cannot afford it on its own and is hampered by the control structure of the Hershey trust.

But Kraft's decision to stick to its initial bid raised some questions about how much it wanted Cadbury and whether it risks losing the chocolate maker altogether.

If they (Cadbury) have their next trading statement and things are looking positive, then you will have a situation where the Cadbury price might have moved away again from where Kraft are trying to pitch this, said Stephen Pope, chief market strategist at Cantor Fitzgerald.

Just going forward with the bid represents a financial commitment from Kraft. The company said last week that the pursuit would cost it about 2 cents to 3 cents a share in the fourth quarter, or about $29.7 million to $44.6 million.

Kraft is offering Cadbury shareholders 300p in cash and 0.2589 new Kraft shares for each Cadbury share, unchanged from the September offer. In a proxy filing, it said it expects integration costs of about $1.2 billion in the first three years after a deal.

Lazard is acting as lead financial adviser to Kraft with Centerview Partners, Citigroup and Deutsche Bank also advising. Goldman Sachs, Morgan Stanley and UBS are working with Cadbury, banking sources said.

(Additonal reporting by Raji Menon, Paul Hoskins, Matt Scuffham, Jessica Hall, Victoria Howley and Rhys Jones)

(1 pound=$1.6713)

(Editing by Michele Gershberg, Andre Grenon, Leslie Gevirtz and Carol Bishopric)