Tier 2 ICT graduate/trainee - how to stay in UK

Hi,
Hope someone can please help.

I am on a Tier 2 ICT graduate visa (12 month, expires Aug 2015) and am looking as to how I can stay in the UK to work. I have been with current firm for 15 months.

Is it possible to :
a) be granted an extension via a Tier 2 ICT LT visa by current employer? If so, can this be extended before expiry of existing visa ? that is if they want to continue my current employment and satisfy job criteria etc...

b) can I apply for Tier 2 General under a different sponsor ? i.e start look for new employment in the UK and thus a new sponsor or is this only possible after 12 month 'cooling-off' period ?

Hope someone can help as very stuck as to understand my options.

Thanks,
Frank

I believe both options are possible if an application is made within the UK. Wait for experts' opinions though.

The T2 ICT Graduate Trainee leave cannot be extended beyond 12 months.

However, you can apply for T2 ICT Long Term Staff entry clearance from home country without cooling-off if your present employer wants to continue employing you (min. salary £41k).

re. T2G - you cannot switch in-country and can only apply from home country after 12 months cooling-off