Navistar International Corp., the Lisle-based truck maker that got an investment this week from Volkswagen, posted third-quarter profit that missed analyst estimates as vehicle sales declined.

Earnings before interest, tax, depreciation and amortization adjusted for some items rose 2.3 percent to $132 million from $129 million a year earlier, the company said in a statement Thursday. Analysts predicted $140.1 million, the average of nine estimates compiled by Bloomberg. The company confirmed its sales and profit forecast for the year.

Navistar, which has activist investor Carl Icahn as its biggest shareholder, posted an 18 percent drop in revenue to $2.1 billion. The company, which has grappled with declining market share, said share of new orders has risen for three straight quarters.

Navistar also said in a regulatory filing that it received a subpoena from the U.S. Defense Department’s inspector general relating to sales of independent suspension systems for military vehicles in 2009 and 2010. The company said it’s complying with the subpoena and can’t estimate the financial impact of the investigation.

The net loss for the quarter, which ended July 31, widened to $34 million, or 42 cents a share, from $28 million, or 34 cents, a year earlier.