UPDATE 2-Spark Infra to open books to KKR consortium after sweetened $3.8 bln bid

* Consortium raises bid price to A$2.95 apiece

* Offer price at 13.5% premium to Spark's last close

* Spark shares jump to top of ASX 200 (Adds Spark comment, background, shares)

July 28 (Reuters) - Spark Infrastructure on Wednesday agreed to open its books to a consortium that includes private equity giant KKR & Co Inc after the group tabled a third buyout offer, valuing the Australian electricity infrastructure investor at A$5.13 billion ($3.78 billion).

The offer, the latest in a flurry of buyout bids in Australia this year, comes nearly two weeks after Spark rejected the consortium's previous proposal.

The group, which also includes Ontario Teachers' Pension Plan Board, raised its price to A$2.95 per share from A$2.80, a 13.5% premium to Spark's last close.

The company considers it would be in the interest of security holders to engage further with the group, Spark said in a statement.

Spark, which has a 49% stake in an electricity distribution network in Southern Australia, has seen its share price surge more than 23% this year following a rebound in infrastructure spending and industrial activity.

The stock jumped as much as 6.9% to A$2.78, rising to the top of the ASX 200 benchmark index.

Spark said it had agreed to provide the consortium with due diligence on a "non-exclusive basis".

KKR and Ontario Teachers' Pension Plan Board did not immediately respond to a request for comment.

($1 = 1.3576 Australian dollars) (Reporting by Sameer Manekar in Bengaluru; Editing by Shinjini Ganguli and Vinay Dwivedi)