(Adds details on deal, paragraph 6, 7) SYDNEY, April 28...

(Adds details on deal, paragraph 6, 7)

SYDNEY, April 28 (Reuters) - Australian lottery operator Tatts Group (TTS) on Friday said a A$6.15 billion cash takeover offer from a consortium backed by U.S. private equity giant KKR & Co was not superior to a cash-and-scrip bid from Tabcorp Holdings (TAH).

"In these circumstances, Tatts is unable to provide due diligence or engage with the Pacific Consortium," the company said in a statement.

The Tabcorp bid valued Tatts at A$4.249 at the close of trade on Thursday, compared with the A$4.21 price of the offer from Pacific Consortium.

Pacific Consortium also includes Macquarie Group Ltd (MQG), Morgan Stanley Infrastructure and First State Superannuation Scheme. Tatts in December rejected an initial proposal from the group.

Tatts and Tabcorp in October said their agreed merger would offer A$130 million a year in synergies.

Under the terms of that deal, Tatts is restricted from engaging in discussions with a rival suitor or providing due diligence access unless it determines the competing proposal would be reasonably expected to result in a superior offer to the Tabcorp bid.

Tatts is a prized asset given the lucrative and reliable earnings from its lotteries business, which benefits from monopoly licences. It also owns a smaller wagering business that competes against Tabcorp, the nation's largest betting operator.