Standard Chartered warned on Thursday that it now expects to pay a total of $670m (£415m) to US regulators to settle allegations that it breached sanctions with Iran.

In a trading update, the bank admitted it expected to pay another $330m on top of the $340m paid to New York's department of financial services (DFS) for scheming to hide billions of pounds of transactions – some $250bn – from the authorities over a decade. The DFS claimed this left the financial system susceptible to "terrorists" and "drug kingpins" although the bank insisted it had not breached sanctions to the extent claimed by the regulators.

The bank, led by Peter Sands, admitted that pre-tax profits would be battered by the fines. "Profit before tax for the group is expected to grow at a mid single digit rate. Excluding the NY DFS settlement profit before tax is expected to be up by a double digit percentage," the bank, a familiar presence on high streets across Asia and Africa, said.

The bank's shares rose almost 1% to £15 because even though profits will be dented they will still be up on last year. It will be the 10th straight year of increases, which continued even through the financial crisis.

"The group remains in active and constructive discussions with the other US agencies on the resolution of the group's historical US sanctions compliance. We anticipate that these discussions will conclude very shortly and are likely to result in the group paying a sum of approximately US$330m," the bank said. The other authorities include the Federal Reserve and the Office of Foreign Assets Control.

Richard Meddings, the bank's finance director, said that he expected the settlement to come "very soon".

Until the DFS allegations the bank was regarded as having a reputation untarnished by the financial crisis but it settled with the US regulator in August after allegations that one its top bankers – believed to be Meddings – had exclaimed "you fucking Americans" when warned about the potential violations of sanctions. The bank insists the quote is inaccurate.

Sands had been forced to cut short his summer holiday to fly to New York to negotiate a settlement with the DFS at a time when the UK's banks were suffering other embarrassments. Barclays had just been fined £290m for manipulating Libor while HSBC had been accused of laundering money through the US for drug barons in Mexico and has since admitted the penalties for these alleged offences could reach at least £940m.

Sandy Chen, analyst at Cenkos, said: "The total of $670m including the earlier $340m NY DFS settlement is a touch smaller than the $730m that we had pencilled in. Note that (the bank) hasn't been exposed to the Libor and payment protection insurance-related charges that have burdened the other UK banks".

Sands tried to focus on the trading update before its full-year results in February. "Standard Chartered is on course to deliver another strong set of full year results for 2012. We continue to focus on the basics of banking, on maintaining a very strong and conservatively positioned balance sheet, and on the disciplined execution of our strategy. We continue to see significant opportunities across our markets in Asia, Africa and the Middle East," he said.

The bank, unlike its rivals, is taking on staff and expects to employ an extra 1,800 by the end of the year than last year.