WARSAW--Poland's statistics office Friday kept its earlier estimate of third-quarter annual economic expansion at 3.3%, which was driven by fixed investments.

The seasonally-adjusted quarterly figure was also left unchanged at 0.9%.

The third-quarter data showed that investments continued to drive growth in Poland, rising 9.9% on the year, above the 8.7% rise in the second quarter. Exports grew 3.8% on the year.

Poland's domestic demand rose 4.9% in the third quarter while private consumption rose 3.2%.

Write to Martin M. Sobczyk at martin.sobczyk@wsj.com