By David Morgan

WASHINGTON, Oct 1 (Reuters) - U.S. House Speaker Nancy Pelosi and Treasury Secretary Steven Mnuchin were expected to try again on Thursday to reach a deal on COVID-19 relief, while the House of Representatives stood ready for a second day to move a Democratic bill if talks fail.

The two sides appeared to be about $600 billion apart on spending, as lawmakers prepared to depart Washington for the final weeks of the 2020 presidential and congressional election campaign. Mnuchin has offered a proposal approaching $1.6 trillion. House Democrats were poised to vote on legislation containing $2.2 trillion in aid.

A bipartisan deal has been long delayed by disagreements over Democratic demands for aid to state and local governments and Republican assistance for a provision protecting businesses from coronavirus-related lawsuits.

Pelosi and Mnuchin met for 90 minutes in the U.S. Capitol on Wednesday and each emerged pledging to continue discussions.

Mnuchin raised hopes of an agreement by telling reporters that the discussions had made "a lot of progress in a lot of areas."

Pelosi's office was not immediately available for comment. But lawmakers and securities analysts viewed the day's expected talks as a last-gasp effort to secure relief ahead of the Nov. 3 election for tens of millions of Americans and business including U.S. airlines, which were due to begin furloughing over 32,000 workers.

The Trump administration has proposed a $20 billion extension in aid for the battered airline industry, White House chief of staff Mark Meadows told reporters late on Wednesday. The extension would run for six months.

Mnuchin said separately that a deal would also include direct payments to American individuals and families.

Pressure for a deal has been mounting on the White House and Congress, from the devastating effects of a coronavirus pandemic that has infected more than 7.2 million people and killed over 207,000 in the United States.

The House was expected to vote on its $2.2 trillion Democratic package, a day after initial plans for action were delayed to give more time for a deal to come together.

Senate Majority Leader Mitch McConnell, who has not participated directly in the negotiations, said on Wednesday that the House bill's spending total was too high. (Reporting by David Morgan; Editing by Scott Malone and Chizu Nomiyama)