UPDATE 2-Virgin Media to cut workforce by 2,200

* Announces restructuring programme

* Sees annual cash flow improvement of 120 mln stg

* Shares down 4.2 pct at $5.45 by 1513 GMT

(adds share price, background)

LONDON, Nov 11 (Reuters) - British cable TV operator Virgin Media (VMED.O) said on Tuesday it would reduce its workforce by around 2,200 by 2012 as part of a new restructuring process.

The group, which is listed in the United States but operates in Britain, said the changes would improve the efficiency of the business and it expects the majority of changes to be implemented between the end of 2009 and the end of 2010.

A spokesman for the group said Virgin Media had told analysts during a presentation in the United States that it expected improvement to cash flow of up to 120 million pounds ($186.4 million) a year by 2012.

The cable group, which formed from the merger of NTL, Telewest and Virgin's mobile phone division, reported a solid set of third quarter figures last week and said it was showing good resilience in the face of the economic slowdown.

"These changes are critical to ensuring Virgin Media is positioned to compete effectively and deliver on our customers' changing expectations," Chief Executive Neil Berkett said in a statement.

"Over the coming weeks and months, we will be developing more detailed proposals for their implementation."

The news briefly sent shares in the group up 0.5 percent but they were down 4.2 percent at $5.45 at 1513 GMT compared with a lower overall market.

Virgin Media said the decision followed a review launched in early 2008 aimed at making the company more integrated and able to compete. It said it would consult with staff and, wherever possible, look to avoid redundancy by offering alternative roles. (Reporting by Kate Holton; Editing by David Cowell)