BRUSSELS--Universal Music Group has still not filed its offer to European Union regulators over its proposed acquisition of EMI Music, EU antitrust chief Joaquin Almunia said Wednesday.

Regulators have expressed major objections to the $1.6 billion deal, which would create a music behemoth in Europe and give the merged entity a market share of over 50% in some key European countries.

Over the past days, the European Commission team that is reviewing the deal has questioned the company's plan to reduce its market share below 40%, further delaying progress in the negotiations, according to people familiar with the matter.

"We are waiting for the formal presentation of remedies from Universal," Mr. Almunia said during a press conference in Brussels. "Once we receive them...we will market test those remedies and assess the results during August."

The final deadline for regulators to give their decision is the end of September.

Universal is due to pay EMI Music's owner, Citigroup Inc. (C), more than $1.7 billion of the purchase price by early September, regardless of whether regulators have approved the deal by then. Citi and Universal, which is owned by Vivendi SA (VIVHY), have discussed extending the payment deadline by about two months, but haven't reached an agreement.

Write to Vanessa Mock at vanessa.mock@dowjones.com

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