Change of Employer on Tier 2 Intra Company Transfer

Hey All,
I have been doing some serious research but since my problem is a bit unique I could not get a specific answer. I have been in the UK since Feb 2007 on Intra company transfer, was issued a 2 year permit which was renewed in 2009 for 3 years. My limited leave to remain now expires in Feb 2012 which in effect will complete 5 years on Intra company and enable eligibility for Indefinite Leave to Remain.
I have been offered a good position with another company who is on the Register of Sponsors. How easy is it for them to transfer my permit or reapply for my permit under new rules? Will this affect my ILR? Some help & guidance needed. Thanks in Advance