* BetMakers makes A$4 bln proposal for Tabcorp's wagering unit

* Bid higher than offers by Entain and Apollo

* BetMakers shares tank as much as 17%

May 28 (Reuters) - Australia's BetMakers Technology Group Ltd on Friday intensified a three-way bidding war for Tabcorp Holdings Ltd's wagering and media business, offering A$4 billion ($3.1 billion) for the struggling division.

The BetMakers proposal dwarfs separate A$3.5 billion offers by British sports betting firm Entain and U.S.-based investment manager Apollo Management for the Tabcorp unit hit hard by the halt to sporting events and closure of betting shops due to the pandemic.

Tabcorp shares gained as much as 4.2% and scaled a near 3-1/2 year peak. BetMakers, though, slumped nearly 17% on news of the proposal, that will involve A$3 billion in shares and A$1 billion in cash, likely to be funded by debt.

BetMakers, which has market value of close to A$1.3 billion, white-labels platforms and widgets for other firms.

"The market is saying that they (Betmakers) are trying to bite off more than they can chew," said Brad Smoling, managing director at Smoling Stockbroking.

Credit Suisse, which values the unit at roughly the same as BetMaker's proposal, said Tabcorp was more likely to demerge the division than accept the approach.

Doing so would avoid numerous, costly regulatory approvals that would be required in a deal with Betmakers, it added.

Tabcorp said it would assess the BetMakers' offer in the context of a wider review announced in March that included the possibility of a demerger.

Entain and Apollo did not immediately respond to Reuters requests for comment.

In April, Entain had sweetened its earlier bid for the wagering and media business, and just over a week later Apollo revised its own offer to match.

Apollo also made an alternative offer of A$4 billion for Tabcorp's gaming services unit alongside the wagering and media arm. ($1 = 1.2917 Australian dollars) (Reporting by Harish Sridharan and Soumyajit Saha in Bengaluru; Editing by Stephen Coates)