| 1 | SOCIETATEA NATIONALA DE GAZE NATURALE " ROMGAZ " SA | Municipiul Mediaş | Sibiu | 5.227 |
| 2 | OMV PETROM ENERGY SOLUTIONS S.R.L. | Bucureşti Sectorul 1 | Bucureşti | 2.813 |
| 3 | SIEMENS ENERGY S.R.L. | Bucureşti Sectorul 5 | Bucureşti | 1.779 |
| 4 | SNGN "ROMGAZ" SA-FILIALA DE ÎNMAGAZINARE GAZE NATURALE DEPOGAZ PLOIEŞTI SRL | Municipiul Ploieşti | Prahova | 494 |
| 5 | INSTITUTUL NATIONAL DE CERCETARE-DEZVOLTARE TURBOMOTOARE - COMOTI | Bucureşti Sectorul 6 | Bucureşti | 388 |
| 6 | PROSPECTIUNI SA | Bucureşti Sectorul 1 | Bucureşti | 379 |
| 7 | SAIPEM ROMANIA S.R.L. | Sat Ariceştii Rahtivani, Comuna Ariceştii Rahtivani | Prahova | 351 |
| 8 | FALCK FIRE SERVICES SRL | Bucureşti Sectorul 1 | Bucureşti | 344 |
| 9 | WEATHERFORD ATLAS GIP SA | Municipiul Ploieşti | Prahova | 258 |
| 10 | KRAFTANLAGEN ROMANIA SRL | Municipiul Ploieşti | Prahova | 211 |
| 11 | ARMAX GAZ SA | Municipiul Mediaş | Sibiu | 205 |
| 12 | ARGENTA S.R.L. | Loc. Năvodari, Oraş Năvodari | Constanţa | 202 |
| 13 | MECANPETROL SA | Loc. Găeşti, Oraş Găeşti | Dâmboviţa | 170 |
| 14 | GEOSTUD SRL | Bucureşti Sectorul 1 | Bucureşti | 159 |
| 15 | DIETSMANN S.R.L. | Oraş Voluntari | Ilfov | 145 |
| 16 | ROMPETROL WELL SERVICES SA | Municipiul Ploieşti | Prahova | 134 |
| 17 | IPIP SA | Municipiul Ploieşti | Prahova | 130 |
| 18 | ATLAS COPCO ROMANIA SRL | Bucureşti Sectorul 1 | Bucureşti | 120 |
| 19 | INSTITUTUL NATIONAL DE CERCETARE-DEZVOLTARE PENTRU INGINERIE ELECTRICA ICPE - CA BUCURESTI | Bucureşti Sectorul 3 | Bucureşti | 110 |
| 20 | SCHLUMBERGER ROMANIA S.R.L. | Bucureşti Sectorul 6 | Bucureşti | 109 |
| 21 | GAZPET INSTAL SRL | Municipiul Ploieşti | Prahova | 106 |
| 22 | NEWPARK DRILLING FLUIDS EASTERN EUROPE SRL | Bucureşti Sectorul 1 | Bucureşti | 103 |
| 23 | MEGACONSTRUCT SA | Bucureşti Sectorul 3 | Bucureşti | 97 |
| 24 | ROHRER DEPOTS MANAGEMENT S.R.L. | Municipiul Constanţa | Constanţa | 95 |
| 25 | SONOVISION ROMANIA SRL | Municipiul Iaşi | Iaşi | 61 |
| 26 | ANVERGO SRL | Municipiul Târgu Mureş | Mureş | 59 |
| 27 | EDIGO TRANS SRL | Loc. Boldeşti-Scăeni, Oraş Boldeşti-Scăeni | Prahova | 59 |
| 28 | INDEPENDENT OIL TOOLS SRL | Bucureşti Sectorul 1 | Bucureşti | 57 |
| 29 | ODFJELL WELL SERVICES SRL | Sat Ariceştii Rahtivani, Comuna Ariceştii Rahtivani | Prahova | 52 |
| 30 | KATO GROUP SRL | Sat Ploieştiori, Comuna Blejoi | Prahova | 51 |
| 31 | WTS ENERGY GLOBAL SERVICES S.R.L. | Bucureşti Sectorul 1 | Bucureşti | 49 |
| 32 | ECO GEODRUM SRL | Bucureşti Sectorul 1 | Bucureşti | 48 |
| 33 | PEX SRL | Municipiul Ploieşti | Prahova | 43 |
| 34 | NOV GERMANY GMBH CELLE GERMANIA SUCURSALA TÂRGOVIŞTE | Municipiul Târgovişte | Dâmboviţa | 43 |
| 35 | NATIONAL OILWELL VARCO ROMANIA S.R.L. | Sat Negoieşti, Comuna Brazi | Prahova | 40 |
| 36 | NA SOLID PETROSERVE LTD CANADA CALGARY - SUCURSALA ROMANIA | Municipiul Ploieşti | Prahova | 38 |
| 37 | PREMIER SLICKLINE S.A. | Municipiul Câmpina | Prahova | 38 |
| 38 | BOURBON TECH SOLUTIONS S.R.L. | Bucureşti Sectorul 2 | Bucureşti | 35 |
| 39 | CHEMFOR BALKAN S.R.L. | Municipiul Ploieşti | Prahova | 34 |
| 40 | UPETROM 1 MAI MANUFACTURING SRL | Oraş Voluntari | Ilfov | 33 |
| 41 | METALUX SRL | Municipiul Piteşti | Argeş | 31 |
| 42 | SEA PROTECT GROUP SRL | Municipiul Constanţa | Constanţa | 31 |
| 43 | EVDANCO OILFIELD SERVICES S.R.L. | Municipiul Târgovişte | Dâmboviţa | 30 |
| 44 | INSTITUTUL NAŢIONAL DE CERCETARE-DEZVOLTARE PENTRU INGINERIE ELECTRICĂ ICPE - CA BUCUREŞTI SUBUNITATEA ICEMENERG | Bucureşti Sectorul 3 | Bucureşti | 30 |
| 45 | COMES INDUSTRY S.R.L. | Municipiul Piatra Neamţ | Neamţ | 27 |
| 46 | PRIMEX MURES SRL | Municipiul Târgu Mureş | Mureş | 26 |
| 47 | DEPOMURES SA | Municipiul Târgu Mureş | Mureş | 25 |
| 48 | PREPITECH SRL | Municipiul Sibiu | Sibiu | 25 |
| 49 | ECOMED EASTERN EUROPE SRL | Bucureşti Sectorul 3 | Bucureşti | 22 |
| 50 | ERM ENVIRONMENTAL RESOURCES MANAGEMENT SRL | Bucureşti Sectorul 1 | Bucureşti | 22 |
| 51 | EUROHALE ANTREPRENOR SRL | Bucureşti Sectorul 3 | Bucureşti | 20 |
| 52 | DEVELTOR SRL | Municipiul Târgu Mureş | Mureş | 20 |
| 53 | RUXO SERVICE CONSTRUCT SRL | Sat Păuleşti, Comuna Păuleşti | Prahova | 20 |
| 54 | S.M.A.P.E.SRL ITALIA SUCURSALA BUCURESTI | Bucureşti Sectorul 5 | Bucureşti | 20 |
| 55 | ARMOS EXIM SRL | Municipiul Târgu Mureş | Mureş | 19 |
| 56 | OPTIMATIC SOLUTIONS SRL | Municipiul Ploieşti | Prahova | 18 |
| 57 | AS GAZ SERVICII COMPLETE S.R.L. | Municipiul Moineşti | Bacău | 18 |
| 58 | ISOTECH SRL | Municipiul Mediaş | Sibiu | 17 |
| 59 | ARTIMET INDUSTRY SRL | Municipiul Moineşti | Bacău | 17 |
| 60 | YÜKSEL PROJE ANONIM SIRKETI ANKARA - SUCURSALA BUCURESTI | Bucureşti Sectorul 1 | Bucureşti | 16 |
| 61 | TRANSMARIN SRL | Sat Strejnicu, Comuna Târgşoru Vechi | Prahova | 15 |
| 62 | M I PETROGAS SERVICES ROMANIA SRL | Loc. Otopeni, Oraş Otopeni | Ilfov | 15 |
| 63 | LLOYD'S REGISTER (ROMANIA) S.R.L. | Municipiul Constanţa | Constanţa | 14 |
| 64 | PICOIL INFO CONSULT SRL | Municipiul Câmpina | Prahova | 13 |
| 65 | OIL DYNAMICS SERVICES S.R.L. | Bucureşti Sectorul 2 | Bucureşti | 13 |
| 66 | ALCATO GROUP SRL | Municipiul Buzău | Buzău | 12 |
| 67 | VALDRIX - S.A. | Bucureşti Sectorul 2 | Bucureşti | 12 |
| 68 | PETROEST SRL | Municipiul Moineşti | Bacău | 11 |
| 69 | DANAMAR INOVATION SRL | Municipiul Ploieşti | Prahova | 11 |
| 70 | DIETSCON O&M S.R.L. | Oraş Voluntari | Ilfov | 11 |
| 71 | DESPA SRL | Sat Colanu, Comuna Ulmi | Dâmboviţa | 10 |
| 72 | DISTRIGAZ ŞIMIAN S.R.L. | Sat Şimian, Comuna Şimian | Mehedinţi | 10 |
| 73 | ENERGOPETROL COM SA | Municipiul Câmpina | Prahova | 9 |
| 74 | RADTOP SRL | Municipiul Târgu Mureş | Mureş | 9 |
| 75 | IAT ENGINEERING & DESIGN SRL | Municipiul Ploieşti | Prahova | 9 |
| 76 | HIDROGAZ CONSTRUCT AG SRL | Municipiul Piteşti | Argeş | 9 |
| 77 | ALLIED GREEN ENERGY S.R.L. | Bucureşti Sectorul 3 | Bucureşti | 9 |
| 78 | SERVICII SI OPERATIUNI SPECIALE LA SONDE S.R.L. | Municipiul Mediaş | Sibiu | 7 |
| 79 | ROUTE 66 SPEDITION SRL | Municipiul Constanţa | Constanţa | 7 |
| 80 | ROAD CONSTRUCT INDUSTRY SRL | Sat Fundeni, Comuna Dobroeşti | Ilfov | 7 |
| 81 | WEST GAL TOUR SRL | Municipiul Piatra Neamţ | Neamţ | 6 |
| 82 | GLOBAL TECH XPERT SRL | Bucureşti Sectorul 6 | Bucureşti | 6 |
| 83 | GELU & SEBI AUTO SRL | Sat Zemeş, Comuna Zemeş | Bacău | 6 |
| 84 | OILFIELD EXPLORATION BUSINESS SOLUTIONS S.A. | Bucureşti Sectorul 1 | Bucureşti | 5 |
| 85 | FEMARIS SRL | Sat Cihei, Comuna Sânmartin | Bihor | 5 |
| 86 | ALLIED GREEN CO SRL | Sat Diţeşti, Comuna Filipeştii de Pădure | Prahova | 5 |
| 87 | ELEMENTAL ENERGIES S.R.L. | Bucureşti Sectorul 2 | Bucureşti | 5 |
| 88 | TWOALI PRODIMPEX SRL | Municipiul Câmpina | Prahova | 4 |
| 89 | SPIDO TRANSPORT SRL | Sat Lipăneşti, Comuna Lipăneşti | Prahova | 4 |
| 90 | EVDANCO ARTIFICIAL LIFT SOLUTIONS S.R.L. | Municipiul Târgovişte | Dâmboviţa | 4 |
| 91 | E.S. ONE S.R.L. | Municipiul Târgu Jiu | Gorj | 4 |
| 92 | GAN GAZ WELDING S.R.L. | Sat Vârsolţ, Comuna Vârşolţ | Sălaj | 4 |
| 93 | VALCHIR CONSTRUCT SRL | Municipiul Moreni | Dâmboviţa | 3 |
| 94 | ENVIROLAND S.R.L. | Bucureşti Sectorul 5 | Bucureşti | 3 |
| 95 | AI CARTE AI PARTE S.R.L. | Municipiul Buzău | Buzău | 3 |
| 96 | PREMIER WELL SERVICES S.R.L. | Municipiul Ploieşti | Prahova | 3 |
| 97 | OPTIM INSTAL GAZ AO S.R.L. | Sat Valea Adâncă, Comuna Miroslava | Iaşi | 3 |
| 98 | TUBEX SRL | Comuna Daneş | Mureş | 2 |
| 99 | IARINA CONSTRUCT SRL | Municipiul Oneşti | Bacău | 2 |
| 100 | BELA-CONSTRUCT SRL | Comuna Valea Teilor | Tulcea | 2 |
