LONDON (REUTERS) - Standard Chartered Plc said it faces another fine from New York's financial regulator for problems related to detecting transactions vulnerable to money laundering, piling more pressure on the Asia-focused bank and its bosses.

The London-based bank on Wednesday said the New York regulator had identified issues in its surveillance system - part of its anti-money laundering systems and controls - which was likely to result in a monetary penalty, remedial action and an extension of a 2-year monitoring period.

The disclosure was made two years to the day that the New York regulator Benjamin Lawsky said Standard Chartered had broken United States (US) sanctions on Iran by hiding transactions and called it a "rogue institution".

It ended with Standard Chartered paying a US$340 million (S$424 million) penalty to the New York regulator, and a similar amount to other US authorities. This time, the bank is likely to pay a penalty of at least US$100 million, a person familiar with the matter said before the results were released.

Standard Chartered disclosed the investigation as it reported a 20 per cent fall in pretax profit in the six months to the end of June to US$3.3 billion.

The bank had warned in June that profits would be down by about a fifth as its investment bank revenues were hit by weak trading activity.