LONDON (Reuters) -U.S. government support for a "baseless" case alleging asset managers conspired to reduce competition in the coal sector risks undermining its goal of energy independence, BlackRock, the world's biggest asset manager, said on Friday.

The U.S. Department of Justice and Federal Trade Commission on Thursday filed a statement of interest in the case by Texas and 12 other states against BlackRock and fellow large investors Vanguard and State Street Global Advisors (SSGA).

The states claim the companies used their substantial holdings in U.S. coal companies to discourage competition.

"DOJ and FTC's support for this baseless case undermines the Trump Administration's goal of American energy independence," BlackRock said in a statement.

"As we made clear in our earlier motion to dismiss, this case is trying to re-write antitrust law and is based on an absurd theory that coal companies conspired with their shareholders to reduce coal production," it said.

"Forcing asset managers to divest from coal companies will harm their ability to access capital and invest in their businesses and employees, likely leading to higher energy prices."

SSGA also called the case "baseless" in a separate statement, adding "we look forward to presenting the facts through the legal process. Additional filings do not change our assessment".

In its own statement, Vanguard said it had "concerns with many of the legal interpretations promoted by the agencies", but that it "appreciates" their support for passive fund investing, shareholder advocacy for better corporate governance and active investing that doesn't harm competition.

"The facts show Vanguard has stayed well within this construct," it said.