March 15 (Reuters) - Big Un Ltd BIG.AX
* Update on big purchase of bha media pty ltd-big.ax
* Signed share purchase agreement to effect acquisition of bha media pty limited
* "$3m advertising revenue anticipated from bha"
* Acquistion is structured at 4 x EBITA excluding synergies Source text for Eikon: ID:nASXbt0VyM Further company coverage: BIG.AX