May 10 (Reuters) - Oklahoma's attorney general said he is firing the outside legal team hired to defend a state law prohibiting state pension systems from contracting with companies that limit investment in the oil and gas industry, days after a judge temporarily blocked the statute's enforcement.

Republican Attorney General Gentner Drummond in a statement on Thursday said he was firing counsel at the Plaxico Law Firm, which he said was handpicked by state Treasurer Todd Russ to defend the law. Drummond said he would also remove Russ from any decision-making authority over the legal defense going forward.

The decision came after a state judge on Tuesday issued a temporary injunction blocking enforcement of the law in oil-rich Oklahoma. The judge found that a retired state employee who is challenging the measure was likely to succeed in his lawsuit alleging the law violates the state constitution and is too vaguely written.

"It is extremely disappointing that the counsel hired by Treasurer Russ was unable to secure a favorable ruling in defense of Oklahoma's anti-ESG law," Drummond said, referring to so-called environmental, social and governance policies.

"Because of this failure, the law is now on hold and at risk of being struck down entirely. Oklahomans deserve better."

Russ, a fellow Republican, said in a statement he had initially asked Drummond to defend the law in court, only to have those requests rejected, and that he did not believe his decision-making authority could legally be removed.

He added that he saw grounds to appeal the court ruling and that he "had hoped to have the attorney general as my defender all along."

Plaxico attorneys did not respond to a request for comment.

Oklahoma's 2022 law is among dozens of Republican-sponsored ESG bills across the country aimed at protecting fossil fuel companies from climate-driven constraints adopted by some Wall Street firms.

Despite those concerns, major financial institutions have largely rejected calls to divest from the oil and gas industries, and some have scaled back their involvement with groups seeking to pressure major emitters.

The Oklahoma law prohibits state agencies from doing business with financial firms that limit investments in energy companies, and requires the state treasurer to maintain a list of those companies even if they continue to own shares in fossil fuel firms.

Russ last year included BlackRock, Wells Fargo , JPMorgan Chase and Bank of America on the list. (Reporting by Clark Mindock in New York and Ross Kerber in Boston; editing by Nate Raymond and Jonathan Oatis)