From (your company letter head)
To: The employees name

Dear ---

Sub: Termination of Service

This is in continuation to our earlier letter no.----dated---- and the subequent letter no.-----dated-----
Inpite of our repeated request to you for the improvement in your
performance, we have observed that your performance has not been
improved for our expectation and you have also not shown any interest for your improvement, we are left with no option but to forced to terminate your services from the company with effect from ------

By a copy of this letter, we are advising our accounts department to settle your dues if any.

Thanking you,

Yours faithfully
for -----