National Grid US has scored 100% in the seventh annual Human Rights Campaign Foundation's Corporate Equality Index.
The index provides an in-depth analysis and rating of large U.S. employers and their policies and practices pertinent to gay, lesbian, bisexual and transgender employees, consumers and investors.
Of the 584 US companies rated by the survey, 260 scored 100%. The average score was 83%.
Of the 31 companies in the Energy and Utilities sector, 5 (including National Grid) scored top marks. The average score for the sector was 68%.
A copy of the 2009 index report can be downloaded from the HRC website.
National Grid has become the only UK utility to be named for three years in a row in a prestigious list of companies where women want to work.
National Grid beat off competition from some of the world's biggest companies, including retailers, supermarkets and public sector agencies, to be named in The Times/Aurora 'Where Women Want to Work TOP 50'.
Out of a total of 134 businesses considered this year, the company is also one of only 27 to have remained in the top 50 for three years running.
Innovative ideas were the key to success this year, with entrants being asked to submit information in three key areas:
Entry was open to organisations based in Britain with 1,000 or more employees and the full top 50 is published in a special colour supplement in The Times newspaper today.
The Times first joined forces with Aurora -- a recruitment advertising agency with a business and career support network for women -- two years ago to find the top 50 places where women want to work.