NEW YORK/LONDON, June 25 (Reuters) - Investors were watching for ripple effects from the aborted mutiny in Russia, with some expecting a move into safe havens such as U.S. government bonds and the dollar when markets open later on Sunday.

Heavily armed Russian mercenaries led by Yevgeny Prigozhin, a former ally of President Vladimir Putin and founder of the Wagner army, advanced most of the way to Moscow after capturing the city of Rostov but then halted their approach, de-escalating a major challenge. The mercenaries pulled out of Rostov overnight.

Financial markets have often been volatile since Russia invaded Ukraine in February 2022, which caused ruptures in markets and through global finance as banks and investors rushed to unwind exposure.

After Saturday's events some investors said they were focused on the potential impact to safe-haven assets such as U.S. Treasuries and on commodities prices, given that Russia is a major energy and grains supplier.

"It certainly remains to be seen what happens in the next day or two, but if there remains uncertainty about leadership in Russia, investors may flock to safe havens," said Gennadiy Goldberg, head of U.S. rates strategy at TD Securities in New York.

The action sparked attention globally and revived an old fear in Washington about what happens to Russia's nuclear stockpile in the event of domestic upheaval.

"Markets typically do not respond well to events that are unfolding and are uncertain," particularly relating to Putin and Russia, said Quincy Krosby, chief global strategist at LPL Financial.

“If the uncertainty escalates, you’re going to see Treasuries get a bid, gold will get a bid and the Japanese yen tends to gain in situations like this,” Krosby said, mentioning typical safe-haven assets that investors buy when risks rise.

Alastair Winter, Global Investment Strategist at Argyll Europe said that while the de-escalation meant markets may now not react strongly, "Putin has clearly been weakened and there will be more developments."

He saw the U.S. dollar finding "some support as the market returns to speculating over rate hikes and cuts and recession in different economies”.

Erik Myersson, chief emerging markets strategist at SEB, said that commodity markets, being the main transmission channel for Russian political shocks to global markets, would be sensitive to developments ahead.

"We might see a move in Ukrainian assets and emerging market countries that are very dependant on Russian grain or could be providers of fossil fuels," he added.

Stocks have been on a mostly upward path in recent months, which some said could make then more vulnerable to a selloff. Year-to-date the S&P 500 is up 13%, though it has lost steam in recent days, subdued by the prospect of rising interest rates.

Federal Reserve Chairman Jerome Powell gave testimony last week in which he signaled more interest rate hikes ahead.

Rich Steinberg, chief market strategist at the Colony Group in Boca Raton, Florida, predicted that "markets will kind of treat this as another geopolitical risk".

Tina Fordham, founder of Fordham Global Foresight, said she expected little immediate impact.

"But there is more sensitivity and awareness by market participants that this increase in internal tension in Russia could translate into a markets event - there will be some cautious watching," she said. (Reporting by Lananh Nguyen, Sinead Cruise, Megan Davies and Karin Strohecker; writing by Megan Davies; Editing by David Gregorio and David Goodman)