(Updates with more detail from) SYDNEY, Feb 24 (Reuters) -...

(Updates with more detail from)

SYDNEY, Feb 24 (Reuters) - Australia's Asciano Ltd (AIO), the target of a A$9 billion ($6.5 billion) takeover battle that has seen rival bidders merge to make a joint assault, on Wednesday posted a 5.3 percent rise in first-half net profit after increasing coal haulage.

However, revenue at Asciano, Australia's biggest rail and port operator, fell 4.3 percent to A$1.85 billion as strong coal volumes in Queensland state were offset by flat or soft volumes elsewhere in the country.

Statutory net profit for the six months to Dec. 31 was A199.8 million, compared with A$189.7 million a year earlier.

Assuming no material change in the current business environment, Asciano said it continues to expect to report flat to low single-digit earnings before interest and tax (EBIT) growth for the full year.

Canada's Brookfield Asset Management Inc and Australian cargo handler Qube Holdings Ltd (QUB) said on Tuesday they were weighing a joint bid for Asciano .

The ceasefire, if it leads to a concrete offer, would deny the rival firms full control of the Australian freight giant but would spare further delays in clinching a deal as they outbid each other.

It could also circumvent regulators, particularly the Foreign Investment Review Board. The proposal under discussion involves giving Brookfield and Qube joint ownership of Asciano's ports - which the government views as strategic assets that should remain in Australian hands - while their foreign bid partners would own the railways.

Asciano said on Wednesday the A$9.28 all-cash nature of the joint indicative proposal "is likely to be attractive to Asciano shareholders", but noted the discussions are still preliminary.

Given that, it continued to recommend the earlier, separate Qube offer as the only formal bid currently on the table.

Asciano shares closed at A$9.01 on Tuesday. Chief Executive Officer John Mullen said the result was solid, despite ongoing weakness in some parts of the Australian economy that hurt volumes.

The interim dividend was lifted to 13 Australian cents from 8.25 cents previously.