Hire To Contract

Hello,
I am working with an IT firm and we have the contract employees as well. Now, After two years of tenure, we would like to take some of the contract employees on the company payroll.Can you please guide me that as an HR what are the formalities that I need to conduct to take them on company payroll.
- Do we need to give them directly an offer letter the way we give to the new joinee of the organization or Do we need to design some other documentation stating that we have hired them after seeing their performance and all........
- Do we need to keep a record of the contractor documents as well in the potential employees file?
Please do guide me on this.
Thank you all in advance

Sorry for the wrong title....It should be "Contract to Hire"

After collecting the resignations from each contractor you are decided to convert to your payroll,you can issue them fresh offer letter.But be ensure that your contractor will get arrears ,LTA etc etc from your contracting agency.

Hello sanalvayalamannil,
Thank you for your response.I really appreciate it.
I have few more queries:-
-Do we need to maintain their resignation and experience letters in their individual files?(which will be given by contract agency)
- Isn't it necessary to have a certain gap between this duration? (eg; Once they serve their notice period, given by contract agency, Can we offer them an appointment letter very next day?Is It possible?
Waiting for the valuable reply.

hmm that irony why people with HR back ground have no knowledge about simple things .
it seems the guy is from sales .

Give a break in service. It is ideal. Further, why personal folders are maintained in HR department, all the documents concerning resignation and new joining formalities need to be recorded and filed away in respective folders for future reference if any.
However, before taking any action, call the contractor, talk to him about the proposal. Contractor may not be happy, on the one hand, since you will be depriving him of his income. However, you should convince him that he can recruit more people for his agency by highlighting the fact that you are taking on board some of the best performers. This way, his disappointment may be slightly toned down.