Guinness announced Sunday it is dropping its sponsorship of the annual St. Patrick's Day Parade in New York City due to the parade's rule that effectively bars LGBT groups from participating in the parade.

"Guinness has a strong history of supporting diversity and being an advocate for equality for all," the company said in a statement. "We were hopeful that the policy of exclusion would be reversed for this year's parade. As this has not come to pass, Guinness has withdrawn its participation. We will continue to work with community leaders to ensure that future parades have an inclusionary policy."

The move comes just days after Heineken announced it is backing out of the parade, which kicks off at 11 a.m. on Monday in Midtown, and is expected to draw more than one million people. In a similar boycott due to LGBT exclusion, Sam Adams Beer skipped the St. Patrick's Day Parade in Boston on Sunday.

Specifically, the parade forbids participants from identifying and displaying their sexual orientation in the parade. New York Mayor Bill De Blasio, citing the policy, is the first mayor in 20 years to skip the parade. On Sunday, Boston Mayor Martin Walsh, too, declined to march in his city's popular St. Patrick's Day Parade.

With the loss of Heineken and Guinness, Ford Motor Company is the only remaining major American corporate sponsor of the parade, according to GLAAD, an LGBT advocacy organization. The company, which has a 100 rating on the Human Rights Campaign's Corporate Equality Index, on Friday told CNBC in part, "Ford Motor Company is involved in a wide range of events and organizations in communities across the country and around the world, including long-standing participation in this parade."

Over the weekend, the Stonewall Inn, a historic LGBT bar in New York, said it would cease offering Guinness and would dump the stout beer in the streets if the company didn't back out of the parade. Those plans have been cancelled and Stonewall plans to continue carrying the beer, according to GLAAD, which applauded Guinness' withdrawal.

"Today, Guinness sent a strong message to its customers and employees: Discrimination should never be celebrated," said GLAAD CEO & President Sarah Kate Ellis. "As a gay mom who has fond memories of the New York City St. Patrick's Day Parade, it saddens me that I can't give those same memories to my own kids because my family isn't welcome. Hopefully, as parade organizers realize that anti-LGBT discrimination is not supported by sponsors, or many Irish New Yorkers, they'll see that families like mine should be part of the celebration."

Neither Ford nor HRC responded to requests Sunday for comment on Ford's sponsorship.