The British Army has become the 400th member of the Diversity Champions programme run by gay equality organisation Stonewall.
The scheme promotes best practice and gives organisations guidance and advice on how to create equality in the workplace.
The Royal Navy and Royal Air Force are already members, alongside companies such as Barclays and IBM and many public sector bodies.
The Army will be working with Stonewall to promote good working conditions for all existing and potential employees and to ensure equal treatment for those who are lesbian, gay and bisexual.
LGB people have been allowed to serve in the Armed Forces since 2000.
General Sir Richard Dannatt, Chief of the General Staff, said he was delighted by the decision and is looking forward to working with Stonewall.
“One of the Army’s six Core Values is ‘Respect for Others’ and it is therefore our absolute duty to treat our fellow soldiers as we would wish to be treated ourselves,” he said.
“Discrimination against those in the Army who are lesbian, gay and bisexual does not give them a chance to contribute or to play a full part in the teams that are vital for our success on operations.
“Respecting others is therefore part of the trust that has to exist between soldiers, and the nation’s values of tolerance, decency and quality must be reflected in the Army.”
Last weekend all three branches of the Armed Forces marched in uniform in the Pride London parade.
While uniformed gay and lesbian members of the Royal Navy were in force at Pride London in 2006 and 2007, until this year the three services had taken different attitudes.
A series of talks between Pride and the MoD, convened by the Equality and Human Rights Commission and Stonewall, overturned the ban.
Last year the RAF announced that personnel who wore uniform to march in the Pride parade in London would face disciplinary action and the Chief of the General Staff issued orders banning LGBT Army staff from marching in uniform at the event.
General Dannatt was said to be concerned with a possible breach of the Queen’s Regulations, which bar military personnel from taking part in political activities.
However, even before today’s announcement the needs of LGBT service personnel were being considered.
In November the third Joint Services Lesbian, Gay, Bisexual and Transsexual conference took place.
All three services approved the two day event, at which more than 100 personnel were updated on developments in diversity training and participated in presentations and workshops.
In June 2007 Wing Commander Phil Sagar, who runs the armed forces joint equality and diversity training centre, issued an apology to the thousands of gay men and lesbians who were discharged from the British Armed Forces because of their sexuality.
Stonewall’s chief executive Ben Summerskill said he was delighted that the Army had decided to join the Diversity Champions programme.
“This sends out a very powerful message,” he said.
“The Army is a 21st century employer which wants to recruit, recognise, and support the very best staff regardless of background.
“Good employers understand that providing support for all their staff enhances operational effectiveness.
“We know that this decision has been welcomed not only by personnel in the UK but also by lesbians and gay men currently serving on operations in Iraq, Afghanistan and Kosovo.”
Members of Stonewall’s Diversity Champions programme now collectively employ more than four million people.