SYDNEY, April 19 (Reuters) - A consortium backed by U.S. private equity giant KKR & Co offered A$6.15 billion ($4.65 billion) cash for Australian lottery operator Tatts Group Ltd, threatening an agreed merger with Tabcorp Holdings Ltd, two sources familiar with the situation said on Wednesday.
The sources, who were not authorised to speak publicly, told Reuters a letter offering A$4.21 a share had been sent to the Tatts board on Tuesday evening.
Tatts in October agreed to accept a cash-and-scrip proposal from betting group Tabcorp to form an Australian gambling powerhouse.
Tatts shares closed at A$4.35 a share on Tuesday. ($1 = 1.3226 Australian dollars) (Reporting by Jamie Freed; Editing by Andrew Hay)