Roughly one quarter of the corporate donors to New York City’s annual Pride festivities have either canceled or scaled back their support this year, citing economic uncertainty and fear that the Trump administration could punish corporations it viewed as supporting a celebration of gay and transgender rights.

Almost all the biggest donors to last year’s celebration have pulled back, and the retreat has been seen at all levels of sponsorship, according to a spokesman for Heritage of Pride, which produces the events. That has posed a fresh challenge to the organization, which has operated at a significant financial loss since before the pandemic.

The spokesman, Kevin Kilbride, said the funding shortfall may force the organization to downsize or cancel some of its June events or other initiatives it runs throughout the year, such as a community grant program that distributes money to smaller L.G.B.T.Q. organizations in New York.

“The vast majority of what we have heard is that folks are treading carefully from an economic perspective,” said Mr. Kilbride.

Corporate representatives have been more guarded when discussing the political environment, he said, “but some folks have definitely mentioned the fear of potential blowback from the Trump administration if you are a big corporation and you are publicly supporting D.E.I. initiatives.”

The retreat of corporate sponsors, including Mastercard, Nissan and Garnier, follows years of wavering support from companies for L.G.B.T.Q. causes. It has left Heritage of Pride facing an unexpected shortfall of an estimated $350,000, a difficult blow for an organization whose spending has significantly outstripped its income every year since 2019, when it hosted WorldPride, a much larger global gathering.