SYDNEY/HONG KONG (Reuters) - Investment bankers are bracing for the start of a landmark legal case about alleged cartel activity in Australia’s financial sector, nervous the proceedings could lead to increased scrutiny and tougher measures from regulators worldwide.

FILE PHOTO: A pedestrian is reflected in the window of a branch of the Australia and New Zealand Banking Group (ANZ) in central Sydney, Australia, October 25, 2017. Picture taken October 25, 2017. REUTERS/Steven Saphore/File Photo

Australian authorities filed criminal charges in June against the local units of Citigroup C.N, Deutsche Bank DBKGn.DE, Australia and New Zealand Banking Group ANZ.AX and six bankers over a $2.3 billion stock sale.

Most past investigations into cartels by the Australian Competition and Consumer Commission (ACCC) have looked at trade in goods. This is the first time a probe has led to charges alleging criminal cartel conduct in the financial sector.

Lawyers representing the banks and the six bankers are due to appear in court in Sydney on Tuesday, although hearings are not expected to begin for several months.

WHAT ARE THE CHARGES?

The charges are linked to an August 2015 sale of $2.3 billion worth of new ANZ shares and the subsequent trading of some of the shares by two of the underwriters - Deutsche Bank and Citigroup. All three have denied wrongdoing and said they will fight accusations.

JPMorgan JPM.N, which also underwrote the capital raising, has not been charged and has not commented on the case.

Charges have also been brought against six executives - ANZ’s former treasurer Rick Moscati; Citi’s former Australia head Stephen Roberts, current local head of capital markets John McLean, London-based head of foreign exchange trading Itay Tuchman; and Deutsche’s former local chief Michael Ormaechea as well as former local capital markets head Michael Richardson.

None of the executives have commented publicly so far.

An ANZ spokesman declined to comment on behalf of Moscati when Reuters contacted the bank on Friday.

WHY DOES IT MATTER?

For investment banks, the case will set a precedent in an area of financial markets activity that lacks clear rules and has never been tested in the courts, according to Citi.

“Underwriting syndicates exist to provide the capacity to assume risk and to underwrite large capital raisings, and have operated successfully in Australia in this manner for decades,” Citi said when the case was first made public.

A Citi spokeswoman declined to comment any further when contacted by Reuters.

The fear is that a court hearing involving such high-profile firms and individuals might prompt regulators to take a fresh look at equity deals.

“These aren’t just criminal charges at the trader level, or someone in operations, these are very senior people who have been charged,” said Ben Quinlan, CEO of consultancy firm Quinlan & Associates.

Cartel charges in Australia come with a maximum penalty of three times the profit made from the cartel activity or 10 percent of a firm’s revenue. Penalties for individuals found guilty carry fines or a maximum 10-year jail term.

OTHER AUSTRALIAN BANKING SCANDALS?

The Australian Securities and Investments Commission has sued ANZ over the same share placement.

The regulator said ANZ broke company laws by failing to tell investors that its underwriters had bought about A$791 million ($558 million) of the total it was trying to sell.

Regulators are under pressure to rein in Australia’s finance sector, as a powerful public inquiry, or Royal Commission, airs almost daily allegations of misconduct.

The commission has issued a scathing interim report saying big banks and wealth managers had pursued profit ahead of customer interests and viewed regulatory compliance as a cost rather than a guide to proper conduct. Several other scandals have engulfed Australian banks, ranging from rate-rigging to money laundering.

WHAT NEXT?

The cases against all parties involved are listed as to be “mentioned” on Tuesday’s calendar for Sydney’s Downing Local Court. Prosecutors told Reuters that the people accused have been excused from being present as it will be an administrative affair where a timetable for future hearings will be set.

Meanwhile, the Royal Commission continues, and ANZ alongside Australia’s other three major banks are scheduled to face questioning over the interim report before a parliamentary committee in Canberra this week.