(Los Angeles, California) An estimated 1,200 Irish-born men and women are living with a same-sex partner in the United States according to a new research study by a University of California think tank.

Added to the more than 2,000 same-sex couples living in Ireland, U.S.-based same-sex couples that include an Irish-born partner would account for more than a third of these couples, the Williams Institute on Sexual Orientation Law and Public Policy has found.

The study was released as the Irish government begins work to enact a civil partnership law that would for the first time offer formal legal recognition to same-sex couples in the Republic of Ireland.

Institute researchers based their conclusions on data from the US Census Bureau.

The study also found that than 500 Irish born same-sex partners are not US-citizens and may be among those most likely to return to Ireland to take advantage of a civil partnership law.

Two-thirds of Irish-born same-sex partners in the US are women.

Irish-born same-sex partners are highly educated - more than four in ten have a college degree and more than one in seven couples that include an Irish-born partner are raising children.

"Irish policy makers should look beyond their shores when they consider the possible effects of civil partnership legislation, some of which might be good for the Irish economy," said study author Gary Gates, Senior Research Fellow at the Williams Institute.

"Such legislation could help to entice a very talented group of Irish-born emigrants back to their homeland."

The study concludes that the legislation could make it easier for global companies to move lesbian and gay employees, their partners, and families from one country to another without risking the economic penalties and logistic challenges associated with non-recognition of their relationships.

Gates notes that, "without legal recognition, it can be difficult for partners of gay and lesbian employees to obtain work permits and they can be subject to challenge regarding their parental rights."

The Irish government says that civil partnership legislation to be brought in this spring.

It will provide same-sex couples with most of the rights and obligations of marriage, but without the name.

A private members bill was introduced last year by Labor Party justice critic Brendan Howlin and was modeled after Britain's civil partner law.

At the time Prime Minister Bertie Ahern said that the bill equated civil partnerships with marriage and after warning the legislation would be rejected by the Supreme Court Parliament his government voted against the measure.

A clause in the constitution says the government must protect the institution of marriage.

Last year two government committees recommended civil partnerships but without many of the rights of marriage, including the right of couples to adopt children.

Recent public opinion polls show that 84 percent are in favor of some recognition of same-sex couples while 53 percent would allow gay couples to marry.