| SC 13G/A | 2009-02-10 | San Faustin N.V. | TENARIS SA | 717,440,187 | 60.8% | EDGAR |
| SC 13G/A | 2008-02-07 | SIDERTUBES SA | TENARIS SA | 713,605,187 | 60.4% | EDGAR |
| SC 13D | 2007-02-21 | TENARIS SA | HYDRIL CO | 1,035,208 | 5.4% | EDGAR |
| SC 13G/A | 2007-02-13 | SIDERTUBES SA | TENARIS SA | 713,605,187 | 60.4% | EDGAR |
| SC 13G/A | 2006-02-06 | SIDERTUBES SA | TENARIS SA | 713,605,187 | 60.4% | EDGAR |
| SC 13G | 2004-02-03 | SIDERCA SAIC | TENARIS SA | 711,238,187 | 60.3% | EDGAR |
| SC 13D/A | 2003-09-16 | TENARIS SA | TUBES OF STEEL OF MEXICO SA | 338,927,728 | 99.9% | EDGAR |
| SC 13D/A | 2003-08-12 | TENARIS SA | TUBES OF STEEL OF MEXICO SA | 320,414,223 | 94.4% | EDGAR |
| SC 13D/A | 2003-04-03 | TENARIS SA | TUBES OF STEEL OF MEXICO SA | 324,064,223 | 94.5% | EDGAR |
| SC 13G | 2003-01-23 | TENARIS SA | SIDERCA SAIC | 991,085,542 | 99.1% | EDGAR |
| SC 13G | 2003-01-23 | SIDERTUBES SA | TENARIS SA | 710,923,257 | 61.2% | EDGAR |
| SC 13D/A | 2002-12-20 | TENARIS SA | TUBES OF STEEL OF MEXICO SA | 324,064,223 | 94.5% | EDGAR |
| SC 13D/A | 2002-11-14 | TENARIS SA | TUBES OF STEEL OF MEXICO SA | 174,114,015 | 50.8% | EDGAR |