** Blackbaud's shares BLKB.O rise 2.2% to $78.40 premarket
vs Clearlake Capital's buyout offer of $80/shr in cash
** Top shareholder Clearlake Capital's raised offer values
the cloud software provider at $4.3 bln
** Blackbaud rejected PE firm Clearlake's $71/shr offer in
March last year, saying it undervalued the company
** BLKB's stock has surged about 33% since that offer; it
has lost 11.5% this year
(Reporting by Harshita Mary Varghese in Bengaluru)
((HarshitaMary.Varghese@thomsonreuters.com))