An ExxonMobil subsidiary did business with three countries under US sanctions as state sponsors of terrorism while President-elect Donald Trump's pick for Secretary of State, Rex Tillerson, was a top executive, filings have shown.

Documents brought to light by a Democratic research group, American Bridge, and first reported by USA Today state that a European subsidiary of the oil giant had sales with Iran, Syria and Sudan in 2003, 2004 and 2005. The European company, Infineum, is 50% owned by ExxonMobil.

USA Today reported that the company had sales totalling $52.3m (£43m) to Iran, $1.1m to Sudan and $600,000 to Syria. Tillerson was a top executive at the company while these deals were happening though he did not become CEO until 2006.

A spokesperson for ExxonMobil, Alan Jeffers, told IBTimes UK that the documents were freely available disclosures of "legal dealings in Iran, Syria and Sudan during a three year period".

"We explained to the SEC [Securities and Exchange Commission] that they were not material and given that they were all in compliance of the law, there was no impact of reputation".

Jeffers said that Tillerson will already be aware of the deals as SEC letters had been addressed to him as CEO but did not know whether he would have been aware while the deals were taking place: "They're not huge, significant deals, they're sales of some chemical products of a third-party non-US company of which we owned an interest but did not control.

"Under the sanction laws at the time that was acceptable. We had no management control, it was an independently-operated company of which we owned shares."

A statement from the company said that the filings were "routine" and ended with the SEC taking no further action: "ExxonMobil does not have any operations – oil fields, refineries, offices or employees – in Iran, Syria or Sudan. The company had limited business transactions in the countries, which were in compliance with all laws.

"We strictly comply with all applicable regulations regarding such contacts, and the contacts are made only after legal advice was rendered as to what was allowed under current sanctions."

The news is likely to become part of Tillerson's senate confirmation hearing on Wednesday (11 January). This was already expected to be contentious due to the former CEO's links to Russia and Vladimir Putin.