The company said its unplanned expenses will amount to about $2.8 billion in 2024

Volkswagen lowered its sales margin forecast for the year Tuesday, saying the possible closure of an Audi electric-vehicle plant in Brussels would have a significant effect on Volkswagen’s results.

The German car manufacturer trimmed its guidance for 2024 operating return on sales to a range of 6.5% to 7% from 7% to 7.5% due to the potential closure and other unplanned expenses.

The company’s leadership was informed that the supervisory board of Audi decided at a recent meeting to support an information and consultation process at the Brussels site as required by Belgian law, citing demand for the Audi Q8 e-tron model in certain markets. The site may be closed at the end of the review process, Volkswagen said.

The company said its unplanned expenses will amount to about 2.6 billion euros, or $2.81 billion, in 2024. They include exchange rate losses related to the deconsolidation of Volkswagen Bank Rus in the Financial Services Division, charges connected to the planned closure of a MAN Energy Solutions’ gas-turbine operations, and costs announced in April from termination of administrative personnel.

Volkswagen is expected to publish its half-year financial report Aug. 1.

Write to Victor Swezey at  victor.swezey@wsj.com