Spells out U.S. Justice Department in paragraph 4

By Jody Godoy and Mike Scarcella

June 3 (Reuters) - Alphabet's Google GOOGL.O has hired Donald Verrilli Jr, the U.S. solicitor general during the Barack Obama administration, to appeal a judge's ruling that the tech titan has an unlawful monopoly in online search, Google confirmed on Tuesday.

Verrilli's hire is a key first step in Google's legal fight to undo the ruling, which it has said could pose a threat to its business.

U.S. District Judge Amit Mehta last year ruled Google holds an unlawful monopoly in online search and related advertising, and is considering proposals to make the tech titan sell off its popular Chrome browser, or share data that CEO Sundar Pichai says would allow competitors reverse engineer its search engine.

Google has argued the U.S. Justice Department failed to prove that competition was harmed by its exclusive agreements with device makers such as Apple to preload Google as the default search engine on new devices. The company has recently begun loosening its agreements to allow partners including Samsung to load rival apps.

Verrilli, who as solicitor general was the Obama White House's top Supreme Court advocate, is known for his work successfully defending the Democratic president's signature domestic healthcare law.

He will represent Google in its planned appeal to the U.S. Court of Appeals for the D.C. Circuit, where Democratic-appointed judges outnumber Republican ones 9 to 6.

Verrilli is separately the lead lawyer for law firm Susman Godfrey in its lawsuit against the Trump administration over an executive order that restricted its business. A judge in April blocked key provisions of the order.

Verrilli is representing hundreds of other firms that filed a court brief denouncing Republican President Donald Trump’s attacks on prominent law firms.

He is also representing U.S. Copyright Office Director Shira Perlmutter in a lawsuit challenging her firing, and the National Endowment for Democracy in a case accusing the Trump administration of illegally withholding funds.

Verrilli's firm Munger Tolles has represented Google in other lawsuits. The firm, whose founders include the late Charlie Munger, has counted Berkshire Hathaway and Bank of America as some of its other clients.

(Reporting by Jody Godoy in New York and Mike Scarcella in Washington; Editing by David Bario)