BRUSSELS (Reuters) - The European Commission on Friday said it had opened an in-depth investigation into the proposed $85 billion (60.28 billion pounds) merger of industrial gases groups Linde (>> Linde Group (The)) and Praxair (>> Praxair), saying it feared reduced competition for some crucial gases.

The Commission, which acts as the competition supervisor in the European Union, said it was particularly concerned about the merger's impact in the markets for oxygen and helium.

"Gases – like oxygen and helium – are crucial inputs for a large variety of products we use every day," Competition Commissioner Margrethe Vestager said in a statement.

"We will carefully assess whether the proposed merger between Praxair and Linde would lead to higher prices or less choice for European consumers and businesses," she added.

The planned all-share merger of equals between the German and the U.S. group, which was agreed in June, would create the world's biggest industrial gases group, ahead of France's Air Liquide (>> Air Liquide), with total revenue of $28.7 billion and 88,000 staff.

The companies said they had set a "pain threshold" of divestments that regulators could require beyond which a merger would no longer make sense.

If regulators demand the disposal of businesses with more than $3.7 billion in sales or $1.1 billion in earnings before interest, taxes, depreciation and amortisation (EBITDA), either party can withdraw without penalty.

The Commission said it had 90 working days, until July 4, to make a decision.

(Reporting by Robert-Jan Bartunek; Editing by Alissa de Carbonnel)

Stocks treated in this article : Air Liquide, Praxair, Linde Group (The)