Gina Rinehart's joint venture company has increased its offer for S Kidman and Co to $386.5 million, but the mining magnate says her own firm Hancock Prospecting will launch a bid in its own right if necessary.

Key points: S Kidman and Co board recommends shareholders accept fresh AOB offer

S Kidman and Co board recommends shareholders accept fresh AOB offer Rival Australian syndicate BBHO says it remains committed to its bid for Kidman

Rival Australian syndicate BBHO says it remains committed to its bid for Kidman Bob Katter wants guarantee majority shareholding won't end up in foreign hands

Australian Outback Beef (AOB), the joint venture which is 67 per cent owned by Hancock and 33 per cent by China's Shanghai CRED, has lifted its bid for the cattle empire by $500,000, surpassing a rival offer from BBHO, a syndicate of Australian graziers.

The Kidman board has unanimously recommended that shareholders accept AOB's increased offer in the absence of a superior proposal, with the deal also requiring approval from the Foreign Investments Review Board (FIRB) and the Chinese Government.

In response, BBHO said it was considering boosting its bid.

Ms Rinehart said the potential to acquire the Kidman business meant a great deal to her personally.

"I am from a station background, having grown up on Mulga Downs and Hamersley stations, both in the outback," she said in a statement.

"I stand behind the bid and should FIRB or PRC [People's Republic of China] approvals not be achieved, then Hancock will proceed with the acquisition on a 100 per cent basis.

"I hope this provides shareholders with significant comfort and that when they consider the offer they can do so in the knowledge that there is no FIRB or PRC execution risk, and further that we have the money to invest to properly maintain the stations and their hard-working staff.

"AOB has the capacity and ability to access additional markets vital to any credible plan to grow Kidman in a sustainable way and without breaking up the core business.

"This will result in valuable jobs being retained in Adelaide and also importantly create more jobs in rural communities where they are so desperately needed."

The BBHO syndicate had previously outbid Hancock for the Kidman empire by more than $20 million. ( ABC News: Amy Phillips )

The offer by AOB excludes the defence-sensitive Anna Creek Station, after the federal Treasurer blocked previous foreign bids for Kidman based on national security grounds.

But the bid is conditional on Anna Creek and its outlying station The Peake being sold and the proceeds returned to Kidman.

"Under the Hancock joint venture the core Kidman business will remain intact and the Kidman staff and legacy will be looked after," Kidman chairman John Crosby said.

The all-Australian syndicate BBHO — made up of four of the nation's wealthiest outback cattle and transport companies — is bidding for the entire business, including Anna Creek Station in South Australia.

The domestic syndicate is yet to launch a formal offer, but does not require Australian foreign investment approval or regulatory clearance by Chinese authorities.

Rinehart 'in driver's seat': commentator

Business commentator Tim Treadgold said the increased offer from AOB was a "classic case" of "the biggest chequebook winning the day".

"It's a business transaction. Rinehart's put the most money on the table, she's got the support of the board and you would have to say she's now in the driver's seat," Mr Treadgold said.

"Half a million dollars is a reasonable amount of money. [But] it only has to be one dollar more and the board of Kidman has no choice but to accept the highest bid.

"To not accept the highest bid would cause them great problems.

"Whether the other people come back and counter-counter-bid, we'll have to wait and see, but at the moment it's a pretty plain vanilla case of the most money wins."

Katter wants ownership guarantee

The federal member for Kennedy Bob Katter called on the Federal Government to ensure the Kidman empire did not end up in foreign hands, even if Ms Rinehart ended up going it alone.

"Will you give guarantees to the Australian people that whoever is purchasing Kidman, it will not simply be transferred a majority shareholding to Shanghai Cred soon after or after the sale to Gina Rinehart, in part or in total?" the leader of Katter's Australian Party said.

"Is there a deal behind the deal?"

Mr Katter said the Government had spoken a lot about foreign ownership during the election.

"A lot of people voted for you on the basis of what appeared to be an undertaking that you were not going to [take] foreign ownership," he said.

"But after the election we're getting no guarantee at all on anything."

98 per cent of Kidman property is leased from State Governments, and any deal must also be approved by the West Australian, Queensland, South Australian and Northern Territory Governments.