OSLO, Nov 25 (Reuters) - Norway's Adevinta, the world's largest classified ads company, posted on Thursday a smaller-than-expected rise in its third-quarter revenue, hampered by weakness in the autos segment, which it said will continue into next year.

Adevinta's July-September revenue rose 6% year-on-year to 386 million euros ($432.74 million), lagging analysts' average forecast of 406 million euros, according to Refinitiv data.

A shortage of semiconductors has constrained global car production this year, hampering sales and, in turn, advertising.

Adevinta's German unit Mobile.de saw a 3% revenue decline in the third quarter, compared to last year.

Adevinta's earnings before interest, web page tax, depreciation and amortization (EBITDA) declined 7% year-on-year to 127 million euros in the third quarter, lagging the 136 million euros expected by analysts, according to Refinitiv.

The company on Thursday set a goal of growing by 15% in the mid-to-long term following its recent $13 billion takeover website of eBay's classified ads unit, but this would not be met next year.

"In 2022, assuming a gradual recovery in the motors market in the second half, we expect core markets revenue growth to be low double-digit," Adevinta said in its earnings report.

The company also announced it plans to divest its operations in Australia and South Africa next year.

($1 = 0.8920 euros) (Reporting by Terje Solsvik; editing by Uttaresh.V)