The upper house of the French parliament has given final approval to a tax on big technology companies, potentially opening up a new front in a trade row between the United States and the European Union.

US President Donald Trump has ordered an investigation into the tax, which could lead to the US imposing new tariffs or other trade restrictions.

"Between allies, we can and should solve our disputes not by threats but through other ways," French Finance Minister Bruno Le Maire told the Senate before the final vote.

The 3% levy would apply to revenue from digital services earned in France by firms with more than €25m in French revenue and €750m worldwide.

France pushed ahead with the tax after EU countries failed to agree a levy valid across the bloc in the face of opposition from Ireland, Denmark, Sweden and Finland.

"France is a sovereign country, its decisions on tax matters are sovereign and will continue to be sovereign," Mr Le Maire said.

Other EU countries including Austria, the UK, Spain and Italy have also announced plans for their own digital taxes.

They say a levy is needed because big, multinational internet companies such as Facebook and Amazon are currently able to book profits in low-tax countries like Ireland, no matter where the revenue originates.

French President Emmanuel Macron has said that taxing big tech more heavily is an issue of social justice.

The European Commission has estimated that multinational digital companies with investments in the EU are on average taxed at a rate 14% below that of other firms.

"We are merely re-establishing fiscal justice. We want to create taxation for the 21st century that is fair and efficient," Mr Le Maire told senators.

"We want to impose on these new business models the same rules that apply to all other economic activities."

Paris has pledged to drop its tax as soon as an international accord is reached at the Organisation for Economic Cooperation and Development on overhauling cross-border tax rules for the digital era. This is expected by the end of 2020.

The French government says the tax does not target US companies and will affect European and Asian firms as well.

The legislation should be enacted within 21 days, a spokeswoman for the Senate said, unless the government or lawmakers ask for a final review by the Constitutional Council.

However, that is unlikely as the bill found wide backing among senators even though some voiced concern about double taxation as corporation tax is based on profit and the digital tax is based on revenues.

Transatlantic trade row rumbles on

The digital tax row is separate from the transatlantic trade row, but could be used by President Trump to try to obtain EU concessions on the trade front.

The US and the EU have threatened to impose billions of dollars of tit-for-tat tariffs on planes, tractors and food in a nearly 15-year dispute at the World Trade Organization over aircraft subsidies given to US planemaker Boeing and its European rival, Airbus.

President Trump has also imposed new tariffs on imports of EU steel and aluminium - and has threatened punitive duties on cars and auto parts if the two sides fail to reach an overall trade deal.

Plans to launch trade talks between Washington and Brussels have, however, been hampered by US tariffs on steel and by EU states' reluctance to include farm products in the talks.