(Adds background, ACCC response)
Nov 17 (Reuters) - An Australian tribunal said on Friday that it would let Tabcorp Holdings Ltd TAH.AX buy lotto giant Tatts Group Ltd TTS.AX for A$6.15 billion ($4.66 billion), after an antitrust regulator raised concerns about the deal.
The Australian Competition Tribunal (ACT), affiliated with the Federal Court, said Tabcorp, the country's biggest horse race betting house, must divest its Odyssey Gaming business in Queensland to complete the deal.
The merger, if it were to go through, will likely result in public benefits, it added.
The deal was cleared in June by the ACT, but antitrust regulator the Australian Competition and Consumer Commission (ACCC) appealed the decision.
Tabcorp and Tatts took the unusual step of applying to the ACT after the ACCC raised concerns about the deal. ACCC then sought a review saying it believed the ACT had misused certain tests to determine if the deal would hurt competition, and that it had given inappropriate weightings to data about the effects of the takeover. shares of Tabcorp and Tatts, which have tried to merge thrice since 2006 in the face of rising competition from online rivals like Britain's William Hill WMH.L and Paddy Power PPB.I , were halted from trading on Friday.
ACCC, in a separate statement, said it would consider the tribunal's reasons for the decision when they are published on Nov. 22.