(Adds background on the lawsuits and detail on the judge’s ruling)

NEW YORK, Nov 16 (Reuters) - A federal judge has blocked Puerto Rico creditors from pursuing litigation to knock down the U.S. territory’s moratorium on debt payments, saying the cases are frozen under a federal law designed to solve Puerto Rico’s financial crisis.

The ruling on Tuesday by U.S. District Judge Francisco Besosa, in San Juan, is a coup for Puerto Rico, which had argued the lawsuits would be too costly to litigate as it battles $70 billion in debt and a 45 percent poverty rate.

The plaintiffs in the four cases - creditors who are owed pieces of that $70 billion, including individuals, hedge funds and bond insurers like National Public Finance Guarantee - had argued their claims were exempt from the so-called automatic stay provision of the law known as PROMESA, signed by President Barack Obama earlier this year.

PROMESA put a pause on litigation over Puerto Rico’s debt, creating a federal board to oversee a workout process that provides for consensual negotiations, or an in-court restructuring mechanism akin to U.S. bankruptcy.

The idea was to avoid years of chaotic and costly litigation in Puerto Rico, which cannot access municipal bankruptcy laws because it is not a U.S. state.

The Obama Administration, which helped push PROMESA through Congress, argued in a court brief that lifting the stay could threaten Puerto Rico’s ability to provide essential government services.

Plaintiffs said their claims were exempt from the stay because they were not seeking to compel payments on their debt, but rather to protect contractual rights they felt were being eroded under a set of orders signed by island Governor Alejandro Garcia Padilla.

The orders let Puerto Rico forgo certain payments and redirect revenues that had been earmarked for debt to cover other expenses instead. The so-called debt moratorium violated the U.S. Constitution, the plaintiffs argued in asking Judge Besosa to declare it unlawful.

But Besosa ruled Puerto Rico would suffer more by having to litigate the cases than the plaintiffs would by having to go through the PROMESA process. “Because the equities tilt against them, plaintiffs have not demonstrated the level of cause necessary to obtain their requested relief,” the judge said.

Besosa was also stern with Puerto Rico, writing that in light of the “benefit and breathing room afforded” by his decision, the island should quickly ramp up restructuring talks with creditors - a strategy Besosa called the “only realistic pathway forward.” (Reporting by Nick Brown in New York; Editing by Jeffrey Benkoe and Andrew Hay)