Service bond - Is it possible for the company to change terms in between?

Hi Friends, I am working in a company. At the time of joining I had a service agreement for 1.5 years and with compensation of 1.25 lakhs.
But after working for three months Now the company wants to change the bond again with 3 years and 5 lakhs as compensation
My question : Is it possible for the company to change in between like this?
And my cost to the company for a year is 3.5 lakhs but the compensation amount is very much high
Whether this 5 lakhs is acceptable?
The reason company gave for the compensation amount is training.. But I don't think proper training is given.
Please let me know what should I do now.

Dear Priyadarsini,
Employment bonds with clauses opposed to public policy against sec.23 of the Indian Contract Act,1872 would not stand Judicial Scrutiny and be declared null and void by the Court. At the most what an employer could demand from an employee for breach of bond condition relating to the minimum length of service would be the liquidated damages relating to the amount of money and time invested to train the employee on the job only. As such it can not be any fancy amount or disproportionately longer period of compulsory tenure after such training according to the employer's whims and fancies. Besides, a bond once executed can not be modified during the course of its operation as per the personal convenience of one party without the consent of the other.
Therefore, you have got the legal right to reject such a move of the employer provided you are bold enough to withstand the possible retaliatory maneuveres from his side.

Hi
As rightly pointed by the learned member Mr Umakanthan, it all depends whether you are desperate to stay in the same company or would like to move out and try your luck elsewhere for employment. If you are ready to take a chance refuse to sign the new bond but put it diplomatically that the company had an existing bond in place and you do not feel like having any change in the same. Wait for an answer before you reject their new bond proposal. If it is reasonable the employer can have it but not otherwise. End of the day it boils down to the individual who is affected by such a covenant. Think twice before shooting any email/letter that might boomerang later. Either way move forward with caution and be diplomatic and try to wriggle out of the issue smoothly and avoid confrontation as it will leave only more stressed than getting a solution.
Thanks and Regards

Thanks all for the reply. I'll try to negotiate with them in a diplomatic way