UPDATE 3-Vestas chairman and CFO quit as 2011 swings to loss

* CFO Norremark quits, chairman won't seek re-election

* Posts 2011 operating loss of 60 mln euros

* Sees 2012 revenue of 6.5-8.0 bln euros

* Says to provide guidance on fewer parameters

* Shares plunge more than 13 pct (Adds details, analyst quotes)

COPENHAGEN, Feb 8 (Reuters) - Wind turbine maker Vestas said its chief financial officer and chairman would leave after it sank to a loss in 2011, even weaker than downgraded preliminary results issued just a month ago.

Vestas Wind Systems A/S, the world's biggest wind turbine manufacturer said CFO Henrik Norremark quit after explaining recent profit warnings to the board.

Just last month, Norremark was designated to move from the CFO's job to a new role as chief operating officer that would have put him in charge of the manufacturing units at the heart of its troubles that led to two profit warnings in three months.

The Danish company, which stunned investors on Jan. 3 with its latest profit warning, also said on Wednesday that chairman Bent Carlsen and two other board members would not stand for re-election at the annual shareholders' meeting in March.

Carlsen, aged 66, had for some time been expected to step aside at the next annual meeting, and some investors called for him to leave after the most recent profit warning.

Shares in Vestas, which lost two-thirds of their value last year, plunged 13.3 percent to 57.85 crowns by 0849 GMT.

Formerly a darling of investors, the wind industry has been hit in the economic crisis by overcapacity and sliding turbine prices as well as cutbacks in support for renewable energy by governments forced to plug deficits.

Vestas reported full-year 2011 revenue of 5.84 billion euros ($7.73 billion) and an EBIT margin before special items of negative 0.7 percent.

Vestas said in a statement those figures were sightly below the preliminary figures issued on Jan. 3 "due to later-than-expected deliveries."

In its profit warning in January, Vestas had said that it expected to report revenue for 2011 of about 6 billion euros and an EBIT margin of about 0 percent.

Instead of nil, it reported an operating loss of 60 million euros for 2011.

Vestas forecast a 2012 EBIT margin in a range of 0-4 percent, the first time it gave guidance for this year. The guided margin compares with a forecast given at this time last year for a 2011 EBIT margin of 7 percent.

It forecast full-year 2012 revenues in a range of 6.5 billion to 8.0 billion euros ($10.59 billion), including service revenue which would grow to about 850 million euros.

"The 2012 guidance is softer than expected, and the EBIT margin guidance is weak," Nordea analyst Patrik Setterberg said in a note to clients.

Vestas said that going forward it would provide guidance on fewer parameters than before and would introduce guidance ranges for EBIT, revenue and cash flow that would take into consideration the large fluctuations in those items.

Vestas confirmed on Wednesday that it received in 2011 firm and unconditional orders for turbines with total capacity of 7,397 megawatts (MW) with a value of 7.3 billion euros, in line with its January preliminary announcement.

It forecast 2012 shipments of turbines would reach 7,000 MW, with the present production plans calling for a peak in the middle of the year, though deliveries could fluctuate heavily over the quarters.

Vestas said that its backlog of orders at the end of 2011 totalled 9,552 MW, which it said was worth 9.6 billion euros and was a record-high level. ($1 = 0.7552 euros) (Reporting by John Acher; Editing by Muralikumar Anantharaman, Matt Driskill and Hans-Juergen Peters)