UPDATE 3-AstraZeneca fights Pfizer bid by predicting sales surge - eventually
* Forecasts $45 billion sales by 2023 as new drugs deliver
* EPS growth expected to exceed revenue growth over 2017-23
* Biggest pipeline hopes hinge on new cancer drugs (Adds further comment from CEO, 2016 and 2017 consensus forecasts, more on politics)
LONDON, May 6 (Reuters) - AstraZeneca Plc laid out its defence against Pfizer Inc's $106-billion takeover approach on Tuesday by predicting its sales would rise by three quarters over the next decade, although only after a short-term drop.
With promising new medicines expected to lift annual revenue above $45 billion by 2023, up from $25.7 billion in 2013, selling out to the U.S. group now would deprive investors of huge gains, it argued.
"The increasingly visible success of our independent strategy highlights the future prospects for our shareholders," said Chairman Leif Johansson. "These are benefits that should fully accrue to AstraZeneca's shareholders."
Chief Executive Pascal Soriot said plunging AstraZeneca into a disruptive merger would also jeopardise its ability to deliver on the new drug pipeline, which is expected to account for 30 percent of the 2023 sales total.
Investors and analysts agree Britain's second-biggest drugmaker has an improving experimental portfolio in areas ranging from cancer to asthma, but they remain nervous about the uncertain commercial future of many products.
AstraZeneca has rebuffed three approaches from Pfizer, which wants to create the world's biggest pharmaceuticals company - and cut its tax bill - by buying the group. It said on Friday that the U.S. firm's latest offer of 50 pounds a share "substantially" undervalued the company.
The group has not ruled out a deal altogether, however, and people familiar with the matter said it was willing to talk if there were a compelling offer. Several large shareholders have told Reuters they would be open to a deal at a higher level.
Shares in AstraZeneca were down 2.7 percent at 46.80 pounds at 1510 GMT.
Sales are set to fall over the next three years as older medicines lose patent protection, slipping to $24.5 billion by 2016 and $23.6 billion in 2017, according to Thomson Reuters consensus analyst forecasts.
AstraZeneca has previously said it disagrees with analysts and sees sales back up at last year's level by 2017. Now it is forecasting "strong and consistent" growth from 2017 to 2023, driven by new treatments for cancer, diabetes, heart disease and lung disorders.
It also flagged up a possible therapy for Alzheimer's disease, a notoriously high-risk area for drug development.
Growth in core earnings per share, which excludes certain items, is expected to exceed revenue growth during this period, it added.
Jefferies analysts said the forecasts appeared "overly optimistic" but the detailed product breakdown might help raise the price and cash mix in any deal. In addition to a higher bid, AstraZeneca also insists there should be more cash than the 32 percent suggested by Pfizer, with the balance paid in shares.
AstraZeneca launched its 10-year sales forecast defence salvo a day after Pfizer CEO Ian Read renewed his call for the British company's board to enter talks.
Read insisted his offer was "compelling" and signalled he was now weighing all options, including a possible hostile bid or looking at other targets, though he stressed that buying AstraZeneca remained "Plan A".
Pfizer's pursuit of AstraZeneca has created a political stir in Britain, with critics of the U.S. group's approach fearing that a takeover will lead to big cuts in drug research, despite assurances given by Pfizer to the government.
Officials have said a deal would be a commercial matter for the two companies but business minister Vince Cable said Britain could use its powers to assess if a takeover was in the public interest, while lawmakers called on Pfizer's bosses to appear before parliament.
Most investor interest centres on AstraZeneca's experimental cancer medicines designed to boost the immune system. Such drugs promise to revolutionise treatment of many tumour types and would also complement Pfizer's line-up of oncology medicines.
But AstraZeneca is lagging rivals such as Bristol-Myers Squibb Co, Merck & Co and Roche Holding AG in this field.
"This is a company that has made significant progress in moving its pipeline forward over the last 18 months," said Alistair Campbell, an analyst at Berenberg Bank. "Is it enough on a fundamental basis to justify the current share price? Personally, I don't think so - at least not without the certainty you need in terms of knowing clinical trial outcomes."
Among individual products, AstraZeneca said heart drug Brilinta had the potential to deliver annual sales of around $3.5 billion by 2023, with diabetes and respiratory medicines both adding about $8 billion apiece.
In cancer it forecast potential peak sales of $6.5 billion for its experimental immunotherapy drug MEDI4736 - the product that has excited most interest from investors and analysts.
AstraZeneca said last month it planned to push ahead with late-stage Phase III testing of MEDI4736, following evaluation of positive Phase I data that will be presented at an American Society of Clinical Oncology (ASCO) conference on May 30-June 3.
The detailed presentations on this and other experimental cancer medicines will be important for AstraZeneca and rivals, and could move its shares - but may be just too late for the Pfizer bid battle.
Pfizer has a deadline of May 26 to make a firm offer or walk away under British "put up or shut up" takeover rules.
"They've got drug candidates in what look to be really exciting areas," said Dan Mahony, a fund manager at Polar Capital, who raised his stake in AstraZeneca last year. "But it is not clear to us yet who, across the industry, has the best drug." (Additional reporting by Anjuli Davies; Editing by David Stamp and Will Waterman)