The chief executive of Istanbul’s stock exchange operator has resigned in a move that could be related to Ankara signalling to the US Biden administration that it wants more conciliation in relations.

Hakan Atilla has stepped down ahead of a trial in New York of his former bank, the state-run Halkbank, over allegations that it helped Iran evade sanctions. The board of Borsa Istanbul accepted Atilla’s resignation, it confirmed in a statement.

Atilla was convicted in a New York court in 2017 on bank fraud, money laundering and conspiracy charges for helping Iran bypass US sanctions for its nuclear programme in 2012 and 2013 during the time he served as deputy chief executive at Halkbank. He was named head of Borsa Istanbul, owned by the state’s Turkish Wealth Fund (TWF, or TVF), in October 2019 after the US deported him following a 28-month prison sentence. At the time, the move was widely seen as made by the Erdogan administration as part of its campaign to attack the credibility of the US prosecutions aimed at the alleged sanctions-busting.

The indictment againt Halkbank also accuses “high-ranking government officials” in Turkey and Iran of participating in the laundering scheme, receiving bribes worth tens of millions of dollars. Halkbank has denied wrongdoing and said the transactions were conducted entirely with respect to regulations.

The trial could add tensions to already difficult relations between the US and Turkey.

President Recep Tayyip Erdogan, who has several times asked the US government to dismiss the charges against Halkbank, has taken a conciliatory approach to those relations since Joe Biden was elected US president.

Halkbank has not agreed to appear in court and its legal team is expected to represent it in what will be a rare trial against a financial institution, the Financial Times has reported. Should Halkbank be found guilty and hit with an onerous fine, it could send shockwaves throughout Turkey’s financial system, Wolfango Piccoli, co-president of UK-based consultancy Teneo Intelligence, was quoted as saying by the daily.

“Turkey may see Atilla’s resignation as a gesture, but it’s irrelevant. What is on trial is Halkbank in its entirety and, if it takes a political turn and officials are exposed, potentially the Turkish government,” he said.

Erdogan has pledged political and economic reforms to rebuild Turkey’s credibility with investors. He is due to this week present an economic package with plans for sustainable economic growth and addressing high inflation.

Berat Albayrak, Erdogan’s son-in-law, appointed Atilla to run Borsa Istanbul in 2019. Albayrak resigned as finance minister in November after the central bank burnt up its foreign reserves in a failed attempt at defending the Turkish lira currency while keeping interest rates low. The European Bank for Reconstruction and Development (EBRD) sold its 10% stake in Borsa Istanbul to the TWF after opposing Atilla’s appointment.

“If the aim is an acknowledgment that new personnel need to be installed in key institutions, [Atilla’s resignation] helps to polish the image of Turkey as a destination for investors,” Piccoli was also cited as saying. “But there is a long list of issues, and they may be opting for the easy solution rather than tackling more problematic issues.”

Borsa Istanbul, which is planning a public offering next year, holds its annual shareholders’ meeting on March 26.