By William Schomberg

LONDON, Feb 12 (Reuters) - Global finance chiefs meet onFriday for the first time since Joe Biden replaced Donald Trumpas U.S. president, vowing to rebuild bridges with allies tosteer the world economy out of its deepest slump since the GreatDepression.

U.S. Treasury Secretary Janet Yellen, a familiar face toglobal policymakers from her days in charge of the FederalReserve, will join her counterparts from the Group of Seven (G7)rich nations for the online discussions.

Britain's finance minister, Rishi Sunak, who will co-chairthe talks, wants the meeting to send a fresh signal thattrillions of dollars of stimulus from G7 members will not bescaled back while COVID-19 vaccinations are still ramping up.

Biden has proposed a further $1.9 trillion in spending andtax cuts on top of Trump's $4 trillion. Sunak is expected to saynext month that he will extend his economic rescue programmesand fixing public finances will have to wait.

The meeting will try to revive attempts for a globalapproach to taxing giant digital firms, many of them Americansuch as Amazon and Google, a test case for Washington's returnto engagement with the rest of the world.

The G7 was also likely to help low-income countries raisefunds to fight the pandemic by backing a new allocation of theInternational Monetary Fund's own currency.

The United States, the IMF's dominant shareholder, is opento a new issuance of $500 billion in what would be another shiftfrom the Trump administration's stance, sources said.

As well as the United States and Britain, the G7 includesJapan, France, Germany, Italy and Canada whose finance ministersand central bank governors will be joined by the head of theEuropean Central Bank and the IMF.

British Prime Minister Boris Johnson is due to host thefirst in-person summit of G7 leaders in nearly two years in Junein a seaside village in Cornwall, southwestern England, whichwill focus on rebuilding from the pandemic and climate change.

Trump threw the G7 into chaos in 2018 when he said he wasbacking out of a joint communique after a leaders' summitbecause of a trade dispute with Canada.

Britain wants to make climate change and biodiversity loss atop priority of it G7 presidency ahead of the COP26 conferenceit is due to host in November.(Writing by William SchombergEditing by Chizu Nomiyama)