Donald Trump has picked one of his biggest fundraisers for the position of commerce secretary.

Howard Lutnick, the billionaire founder of the financial firm Cantor Fitzgerald, will be nominated to serve as one of Trump’s principal advisers on commerce and international trade.

In a statement, Trump said Lutnick would “lead our Tariff and Trade agenda” in the role, and also have “direct responsibility” for the Office of the United States Trade Representative, which negotiates trade deals.

The appointment hands Lutnick a key role in the implementation of Trump’s plan to impose steep universal tariffs on overseas imports. While economists and corporate leaders have warned the proposal risks increasing prices for Americans, proponents including Lutnick have claimed it will boost the US economy.

The businessman, and close ally of Trump, had been tipped for the more powerful role of treasury secretary, an appointment that had the backing of another powerful Trump fundraiser, the tech billionaire Elon Musk.

Scott Bessent, an investor and hedge fund manager, has been seen as Lutnick’s closest rival for the treasury. On his social media site last week, Musk wrote: “My view fwiw is that Bessent is a business-as-usual choice, whereas @howardlutnick will actually enact change.”

Lutnick was co-chair of Trump’s transition team. He has championed Trump’s plans to use tariffs on foreign imports to build the US economy – a plan many economists believe will lead to rising inflation. He is also a big backer of loosening regulation of cryptocurrencies.

Trump has known Lutnick, whom he hailed in Tuesday’s announcement as a “dynamic force on Wall Street”, for decades. A self-described fiscal conservative and social liberal, he has donated to Democrats in the past but recently told the Wall Street Journal that “they have moved away from me”.

Cantor Fitzgerald lost 658 employees in the terrorist attacks on the Twin Towers on 11 September 2001. In the decades since he rebuilt the privately held company, it now employs 13,000 people, up from 2,000 before the tragedy.

It is so far unclear how or if he will separate his vast business interests from his powerful government role.

During a rally at Madison Square Garden last month, Lutnick was riffing on what he thinks “Make America great again” actually means when he explained when he believes the US was sufficiently great: 1900. “At the turn of the century, our economy was rocking,” he claimed. “We had no income tax, and all we had was tariffs.”