Infrastructure company Asciano has again increased its stake in pallet and plastic container provider, Brambles, but analysts say a full takeover is not likely.

Brambles issued a 'please explain' notice to Asciano this week, advising the market that Asciano now held 2.19 per cent of its stock.

Today it revealed the stake being held by Macquarie Bank subsidiary Belike Nominees Ltd on behalf of Asciano had risen.

"That sub-account has increased by a further 4,109,975 shares and now holds 35,060,462 Brambles shares, or 2.48 per cent of Brambles issued capital," Brambles said in a statement,

"Brambles will be serving further notices on Belike Nominees Pty Limited (a subsidiary of Macquarie Bank) and the Asciano group today requesting confirmation of the beneficial ownership of the additional shares."

Brambles is demanding Asciano reveals its ownership motivations.

CommSec senior industrial analyst Cassandra Meagher said Asciano's ambitions were probably more modest than some in the market presumed.

"I don't think they'll launch a takeover - it's possible but not probable," Ms Meagher commented, adding that a joint venture was more likely.

"What Brambles could potentially give Asciano is a geographic advantage, Asciano wants to go to the United States or Europe, and Brambles already operates there - a relationship (that) could give them leverage."

Another potential benefit could be a deal on pallet return through Asciano's rail lines.

"There's a natural freight flow of pallets to Western Australia and down to Tasmania, this could be as simple as bringing home the empties."

Complicating matters further is the presence on Brambles' share registry of the company that spawned Asciano, freight giant Toll Holdings.

Asciano was spun out of Toll and listed on the Australian stock exchange in June this year to appease the concerns of the Australian Competition and Consumer Commission.

Ms Meagher said the potential benefits for Toll were to be gained from integrating supply chains.

"With a move to increased automation of distribution centres, a quality-consistent pallet become an integral element of the distribution centre," she said.

Brambles shares were two cents lower at $12.80. Asciano was down 21 cents at $8.14, and Toll fell 22 cents to $12.90.