June 27 (Reuters) - Circor International Inc said on Tuesday it has accepted investment firm KKR's revised offer to buy the industrial machinery maker for $1.7 billion, including debt.

KKR's cash offer of $51 per share is up from its previous $49 per share proposal.

The improved offer comes after Circor received an unsolicited buyout proposal from a third party for $52.65 per share in cash. (Reporting by Aishwarya Nair in Bengaluru Editing by Vinay Dwivedi and Saumyadeb Chakrabarty)