By Terry Wade

HOUSTON (Reuters) - With a number of U.S. states proceeding with investigations of Exxon Mobil Corp's <XOM.N> record on climate change, the attorney general of Massachusetts and investment funds of the Rockefeller family on Friday told a Congressional committee it lacked powers to oversee those probes.

The pushback is the latest chapter in a high-stakes fight between the world's largest publicly traded oil company and a coalition of state attorneys general who have said they would go after Exxon to try and force action to tackle climate change.

The House Committee on Science, Space and Technology last week reiterated demands that state attorneys general hand over any records of consultations the prosecutors had with outside environmental groups before their probes were opened.

Republicans on the committee have said about 20 state officials overreached when they jointly said in March they would participate in inquiries into whether Exxon executives misled the public by contradicting research from company scientists that spelled out the threats of climate change.

State officials have said the committee has no right to get involved.

"The Committee lacks authority to interfere with an investigation by the Massachusetts Attorney General's Office into possible violations of Massachusetts law by ExxonMobil," said a letter to the committee from the office of Massachusetts Attorney General Maura Healey that was seen by Reuters.

In another letter to the House panel seen by Reuters, the Rockefeller Brothers Fund and the Rockefeller Family Fund, two investment funds that have been critical of fossil fuels linked to climate change, said the committee's request "imperiled the funds' First Amendment rights" and said "Congress's investigatory power is not unlimited."

Last week, Exxon asked a federal court to throw out a subpoena that would force it to hand over decades of documents on climate change to Healey's office.

Both sides in the standoff have sought to use the First Amendment of the Constitution, which guarantees freedom speech and freedom of assembly, among other protections, to press their cases.

The House committee has complained the inquiries risk stifling free speech and scientific inquiry, and that state officials were coordinating with special interest groups.

Exxon, which declined to comment on Friday, has repeatedly said that it has acknowledged the reality of climate change for years and communicated this to investors.