Dear Friend
It is very simple and give a letter addressing to union secretary / president
To
The Union Secretary / President
Name of union............
Dear Sir
Sub:Intimation of joint meeting - Reg
Ref: Charter of demands dated ...........as submitted by your union - Reg
With reference to the above, you are hereby informed that our unit head has informed me to convene a joint meeting with your union office bearer at .....AM/PM on ............., so as to enable us to discuss and arrive an amicable settlement on the demands raised by your union vide charter of demands cited in above reference.
Therefore, 6 or 7 executive members from your union are required to attend the said meeting at HR Dept conference Hall at .........AM/PM on .............. The permission for leaving the place of work by union representatives who will participate in the said meeting will be granted by respective service department
Regards