Your attention, please...
It has been decided that...
May I have your attention, please?
...is requested to note that...
...has/have the honor to announce...
...takes the pleasure in announcing that...
...has/have the pleasure to notice/announce (that)...
This is to note/notice/notify/announce that...
It is hereby noted/announced/proclaimed/made public that...
...is/are authorized to invite/announce/declare that...
Under the auspices of..., ...will organize/hold a... match/competition contest between... and... on... in...