(Corrects spelling of "Elliott" in headline)
Feb 25 (Reuters) - Hedge fund Elliott Management increased its offer for network gear maker Riverbed Technology Inc to $21 per share from $19 and said it would not increase the offer "in the absence of private diligence".
The new offer values Riverbed at about $3.36 billion.
The company rejected the earlier $3.08 billion offer on Jan. 15.
(Reporting By Aditya Kondalamahanty in Bangalore; Editing by Saumyadeb Chakrabarty)