Notes to the consolidated financial statements – supplementary information
37. Subsidiary undertakings, joint ventures and associates
Principal subsidiary undertakings
The principal subsidiary undertakings included in the consolidated financial statements at 31 March 2008 are listed below. These undertakings are wholly-owned and, unless otherwise indicated, are incorporated in Great Britain.
| Principal activity | ||
|---|---|---|
| National Grid Gas plc (i) | Transmission and distribution of gas | |
| National Grid Electricity Transmission plc (i) | Transmission of electricity in England and Wales | |
| New England Power Company (incorporated in the US) (i) | Transmission of electricity | |
| Massachusetts Electric Company (incorporated in the US) (i) | Distribution of electricity | |
| The Narragansett Electric Company (incorporated in the US) (i) | Distribution of electricity | |
| Niagara Mohawk Power Corporation (incorporated in the US) (i) | Distribution and transmission of electricity and gas | |
| National Grid Metering Limited (i) | Metering services | |
| OnStream Metering Services Limited (i) | Metering services | |
| National Grid Grain LNG Limited (i) | LNG import terminal | |
| Boston Gas Company (incorporated in the US) (i) | Distribution of gas | |
| National Grid Electric Services LLC (incorporated in the US) (i) | Transmission and distribution of electricity | |
| National Grid Generation LLC (incorporated in the US) (i) | Generation of electricity | |
| New England Electric Transmission Corporation (incorporated in the US) (i) | Transmission of electricity | |
| Nantucket Electric Company (incorporated in the US) (i) | Distribution of electricity | |
| KeySpan Gas East Corporation (incorporated in the US) (i) | Distribution of gas | |
| KeySpan-Ravenswood, LLC (incorporated in the US) (i) | Electricity generation | |
| The Brooklyn Union Gas Company (incorporated in the US) (i) | Distribution of gas | |
| NGG Finance plc (ii) | Financing | |
| British Transco Finance, Inc. (incorporated in the US) (i) | Financing | |
| British Transco International Finance B.V. (incorporated in The Netherlands) (i) | Financing | |
| National Grid Property Limited (i) | Property services | |
| National Grid Holdings One plc (ii) | Holding company | |
| Lattice Group plc (i) | Holding company | |
| National Grid USA (incorporated in the US) (i) | Holding company | |
| Niagara Mohawk Holdings, Inc. (incorporated in the US) (i) | Holding company | |
| National Grid Commercial Holdings Limited (i) | Holding company | |
| National Grid Gas Holdings plc (i) | Holding company | |
| National Grid (US) Holdings Limited (ii) | Holding company | |
| National Grid Holdings Limited (i) | Holding company | |
| KeySpan Corporation (incorporated in the US) (i) | Holding company |
(i) Issued ordinary share capital held by subsidiary undertakings.
(ii) Issued ordinary share capital held by National Grid plc.
Principal joint ventures and associates
The principal joint ventures and associate undertakings included in the financial statements at 31 March 2008 are listed below. These undertakings are incorporated in Great Britain (unless otherwise indicated).
| % ownership | Principal activity | |
|---|---|---|
| Blue – ng (Holdings) Limited | 50 | Holding company |
| BritNed Development Limited | 50 | Interconnector between UK and Netherlands |
| Millennium Pipeline Company, LLC (incorporated in the US) | 26.25 | Gas pipeline construction |
| Iroquois Gas Transmission System, L.P. (incorporated in the US) | 20.4 | Transmission of gas |
A full list of all subsidiary and associated undertakings is available from the Company Secretary & General Counsel of the Company.