Insurance broker Aon has offered concessions to gain EU antitrust approval for its $30 billion bid for rival Willis Towers Watson, a European Commission filing showed on Monday.

The sector’s biggest deal ever comes as insurers grapple with rising claims and new challenges brought on by the COVID-19 pandemic and climate change.

Aon, which clinched the deal a year ago to create the world’s largest insurance broker ahead of Marsh & McLennan Companies Inc, submitted its package to the EU competition watchdog on April 9.

The Commission, which did not disclose details of the concessions, set a July 12 deadline for its decision. It will now seek feedback from competitors and customers before deciding whether to clear or block the deal or whether to seek additional concessions.

Among the EU enforcer’s demands is the sale of the Willis reinsurance business, which Aon has refused, a source has told Reuters. It may also come under pressure to sell the business that provides consulting and administration services to companies on employee retirement and health schemes.