(Reuters) -Australia's biggest energy retailer Origin Energy said on Thursday the "complex" new offer by a Brookfield-EIG consortium to buy out the firm is not in the best interest of its shareholders, but recommended that they back the bid.

The new bid, offered earlier this month, proposes the sale of Origin's energy markets business to Brookfield for A$12.3 billion ($8.00 billion), with a subsequent off market takeover offer by EIG for Origin, subject to certain conditions.

Origin Energy said in a statement that its board, despite terming the new offer "incomplete, complex, highly conditional and not providing sufficient certainty for its shareholders", continues to unanimously recommend that shareholders vote in favour of the bid in the absence of a superior proposal.

"It is also the board's view that the value of the revised proposal does not adequately compensate shareholders, including taking into account the extended timeline that the proposal would require."

The new revised proposal also includes requiring finalisation of various funding arrangements along with a set of regulatory approvals, thereby extending the timeline of the deal, Origin said.

(Reporting by Rishav Chatterjee in Bengaluru; Editing by Shailesh Kuber)