(Reuters) -Microsoft ( MSFT ) has hired a law firm that is fighting back against the Trump administration's legal industry crackdown, dropping another prominent firm that chose to settle with the White House.

Court documents showed Microsoft ( MSFT ) has hired Jenner & Block to replace Simpson Thacher in a Delaware Chancery Court lawsuit over its $69 billion purchase of Activision Blizzard. The filings did not give a reason.

Microsoft ( MSFT ), without elaborating, said in a statement to Reuters that Simpson Thacher continues to represent it on other matters.

Representatives for the firms did not immediately respond to requests for comment.

Jenner and three other firms are suing President Donald Trump's administration over his executive orders that stripped their security clearances, restricted their access to government buildings and sought to cancel federal contracts held by their clients. 

Wall Street firm Simpson Thacher is among nine firms that have collectively pledged nearly $1 billion in free legal services to the White House since Trump launched his pressure campaign on firms that he accused of "weaponizing" the legal system against him. 

Companies can have many reasons for switching legal teams, including to save money or avoid attorney-client conflicts. Jenner has represented Microsoft ( MSFT ) in other cases, court filings show. 

The New York Times first reported Microsoft's ( MSFT ) change in counsel.

Jenner's lawsuit against the Trump administration called the executive order an "unconstitutional abuse of power" that sought to drive away its clients.

It said the order was retribution for its past employment of a prosecutor involved in the U.S. special counsel probe into Russian contacts with Trump's 2016 presidential campaign.

A former top lawyer at Microsoft ( MSFT ) and dozens of other current and former general counsels at major U.S. companies said in a court brief backing Jenner and other firms that Trump's orders force companies "to choose counsel to avoid the President's retribution rather than based on independent business judgment, experience, skill, or expertise."

Simpson Thacher represented Microsoft ( MSFT ) in its acquisition of Activision Blizzard, maker of the popular video game "Call of Duty." The deal, announced in 2022, was the largest-ever in the gaming industry. 

The lawsuit in Delaware claimed Activision improperly approved a draft merger agreement and not the final version. Microsoft ( MSFT ) in 2024 asked a judge to validate the acquisition and deny a $15 million fee request from lawyers who represented an Activision shareholder.