Australian fertility services provider Virtus Health said on Wednesday it will consider a revised buyout offer from minority owner BGH Capital, weeks after it accepted a sweeter bid from rival suitor CapVest Partners.

In a takeover battle that has seen Virtus shares climb 55% since last December, private equity firm BGH Capital, which already owns 19.9% of Virtus, is now offering A$8.0 per share, valuing the in vitro fertilisation (IVF) specialist at A$683.5 million ($518 million) in total.

The revised offer is at a discount of 0.9% to Virtus' last closing stock price, and is 4.6% higher than BGH's previous offer of A$7.65 apiece.

Melbourne-based BGH's new proposed bid comes weeks after Virtus unanimously recommended to shareholders - including BGH - a cash offer of A$8.25 per share from investment firm CapVest, valuing Virtus at A$704.8 million. Virtus' deal with CapVest allows it to consider a superior proposal from BGH or another party.

London-based CapVest did not immediately respond to a Reuters request for comment.

"Virtus board is considering the BGH takeover bid, and in particular, whether it constitutes a 'superior proposal' under the transaction implementation deed signed with an entity controlled by CapVest Partners," Virtus said in a statement.

Shares in Virtus which has operations in Australia, Ireland, Denmark, Britain and Singapore, were up 0.7% at A$8.13 as of 0251 GMT while the broader market was down 0.7%. [.AX]

BGH's new off-market takeover bid is structured as an all-cash offer, with no reliance on any tax rulings or capital returns, the private equity firm said.

The offer would provide shareholders with "an opportunity to divest as much Virtus stock as they deem appropriate" without having to pay brokerage fees, BGH said.

($1 = 1.3200 Australian dollars)