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BRASILIA (Reuters) - Brazilian planemaker Embraer EMBR3.SA has delayed its expected timeline for the closing of a major deal with Boeing BA.N to early 2020, according to a securities filing on Thursday.

Previously, Embraer had said repeatedly that the deal, which will see Boeing buy 80% of its commercial jet division for $4.75 billion, would close by the end of 2019.

The new timeline comes after the European Commission said it would do an extensive investigation of the deal on antitrust grounds. Embraer also said on Thursday it had received approval from U.S regulators.

The deal with Boeing will challenge Airbus SE AIR.PA, which recently bought a controlling stake in the Bombardier unit that competes directly with Embraer's mid-sized commercial planes of up to 150 passengers.

The Airbus-Bombardier deal was approved by all regulators.

Until all approvals are received and other conditions are satisfied, Embraer cannot guarantee that the Boeing deal will keep to its new timetable or be completed at all, it said.

Embraer shares have fallen five days in a row, their longest losing streak in four months, and are down 10% in the last two weeks, underperforming the broader Brazilian stock market.