UPDATE 3-Novo Nordisk says FDA's Victoza feedback delayed

* FDA's formal feedback on Victoza delayed beyond year-end

* Company says expects feedback within weeks

* Plans update on Feb 2 if feedback not received earlier

* Shares down 0.5 pct (Adds analyst quotes; updates share price)

COPENHAGEN, Dec 30 (Reuters) - Danish drugmaker Novo Nordisk (NOVOb.CO) said on Wednesday that formal feedback from U.S. regulators on its Victoza diabetes drug has been delayed beyond year-end but is expected "within weeks".

Victoza, also known as liraglutide, was approved in Europe in July, but repeated delays in receiving approval for the all-important U.S. market have cast a shadow over Novo Nordisk this year.

Some analysts had expected news from the FDA by year-end, but Novo Nordisk's shares dipped only modestly on the delay.

"Formal feedback from the United States Food and Drug Administration (FDA) regarding liraglutide, a once-daily human GLP-1 analogue, is expected within weeks," Novo Nordisk said in a statement. "Novo Nordisk continues the constructive dialogue with the FDA regarding the regulatory process for liraglutide."

Novo Nordisk will give an update on the regulatory process with its financial results for 2009 on Feb. 2, if formal FDA feedback is not received before then, the company said.

Novo Nordisk shares were off 0.5 percent at 332.25 crowns by 1351 GMT, just slightly weaker than a 0.4 percent drop in the DJ Stoxx European healthcare index .SXDP.

Jefferies analysts said in a note to clients that they had not expected the FDA to complete the regulatory process by year-end and that the stock is a buying opportunity near-term on possible Victoza setbacks as other parts of Novo Nordisk's business are undervalued.

"We would advise caution until this issue is crystallised for Novo Nordisk/Victoza, but would be strong buyers on any major delays or negative opinion if the shares pull back significantly (...)," the Jefferies International note said.

Jyske Bank analyst Frank Horning Andersen also said the delay was insignificant. "We still expect a launch (in the United States) by the end of 2010," he said.

"It is a minor delay. In principle, it is entirely unimportant whether we get a decision on January 15 or December 30," Andersen said.

Novo Nordisk's spokesman Mike Rulis said the company had been "a bit too optimistic" about the timing of the FDA's feedback, but he played down the significance of the delay.

"We have an ongoing dialogue, and nothing new or sensational has occurred during this dialogue, so we are convinced that this is merely an expression that the process of approval is just taking longer than we originally anticipated," Rulis said. Rulis said that only about half of applications are approved by the FDA within 24 months. Novo filed its application for Victoza in May 2008, 19 months ago.

Victoza is a rival to Eli Lilly's (LLY.N) and Amylin Pharmaceuticals' (AMLN.O) Byetta treatment, and Novo Nordisk has said it has potential to be a blockbuster drug, meaning annual sales of more than $1 billion.

Victoza and Byetta belong to the GLP-1 class of drugs that stimulate insulin release when glucose levels grow too high.

Other GLP-1 drugs are also being developed by rival drugmakers, such as GlaxoSmithKline Plc (GSK.L) and Roche Holding AG (ROG.VX). (Reporting by John Acher and Karin Jensen; Additional reporting by Anna Ringstrom and Ole Mikkelsen; Editing by Hans Peters)