UPDATE 3-Three takeaways from Sondland impeachment testimony

(Condenses earlier version)

By Andy Sullivan

WASHINGTON, Nov 20 (Reuters) - A U.S. diplomat provided some of the most significant testimony to date in the impeachment inquiry of President Donald Trump. Here are three takeaways from the testimony on Wednesday of Gordon Sondland, U.S. ambassador to the European Union:

ACTING ON TRUMP'S ORDERS

Sondland said he "followed the president's orders" as he pressured Ukraine to undertake investigations that could boost the president's November 2020 re-election prospects.

Sondland said Trump did not specify what he wanted Kiev to investigate, but told him to work with Rudy Giuliani, Trump's personal lawyer.

Sondland said Giuliani pushed to investigate Burisma, a natural gas company on which Hunter Biden, son of Democratic presidential candidate Joe Biden, served as a director.

He said Giuliani also wanted Ukraine to look into a discredited conspiracy theory that Kiev, not Moscow, interfered in the 2016 U.S. presidential election.

Sondland said he gradually realized the White House was also withholding $391 million in security aid in order to pressure Kiev.

QUID PRO QUO

Sondland said the White House resisted setting up a phone call between Trump and Ukraine's new president, Volodymyr Zelenskiy, and refused to arrange a coveted Oval Office meeting unless the Ukrainian leader publicly promised to launch investigations sought by the White House.

"Was there a quid pro quo? ... the answer is yes," Sondland said.

That contradicts Trump's main defense - that there was no explicit exchange of favors between the two countries.

'NO SECRET'

Sondland said he kept senior administration officials like Secretary of State Mike Pompeo and acting White House Chief of Staff Mick Mulvaney updated about his efforts, contradicting other witnesses who said he was part of a rogue operation that circumvented regular diplomatic channels.

He says he notified Vice President Mike Pence in September that the delayed Ukraine aid appeared to be tied to the demand for investigations.

"Everyone was in the loop. It was no secret," he said.

His testimony could be damaging for Pompeo should he make a bid to run for the U.S. Senate from Kansas.

"You're doing great work; keep banging away," Pompeo told Sondland in early September, according to correspondence cited in Sondland's testimony.

Messages like those could help Pompeo's potential rivals make the case that the secretary of state was more concerned with catering to Trump's whims than ensuring the integrity of U.S. foreign policy.

Pompeo declined to comment on Wednesday. (Reporting by Andy Sullivan; Additional reporting by Doina Chiacu; Editing by Ross Colvin and Howard Goller)