UPDATE 1-Judge rejects Massachusetts challenge to Trump birth control rules

(Adds details from court ruling)

BOSTON, March 12 (Reuters) - A federal judge on Monday rejected a lawsuit by Massachusetts' attorney general challenging new rules by President Donald Trump's administration that make it easier for employers to avoid providing insurance that covers women's birth control.

U.S. District Judge Nathaniel Gorton in Boston dismissed a lawsuit by Massachusetts Attorney General Maura Healey that sought to block rules that provide exemptions from an Obamacare mandate requiring such coverage on moral or religious grounds.

Those rules, announced in October, remain on hold after two other federal judges in California and Pennsylvania in December issued preliminary injunctions blocking the Republican president's administration from enforcing them.

Gorton said that while in contrast to those two states, where there is "no doubt" employers intend to take advantage of the exemptions, "the record is uniquely obscure" as to whether any in Massachusetts would.

He noted that after the new rules were announced, Massachusetts in November enacted a law called the ACCESS Act that required employer-sponsored health plans to cover birth control without imposing co-pays.

As a result, Gorton said that state law provided reasons to believe Massachusetts women were less likely to be affected by the federal rules, undercutting Healey's claim that the state would be injured by them and she had standing to sue. (Reporting by Nate Raymond; Editing by Lisa Shumaker and Grant McCool)