* Graphic: World FX rates in 2020 tmsnrt.rs/2egbfVh.

LONDON, May 25 (Reuters) - Stocks gained modestly on Monday after a survey showed German business morale rebounded in May, while investors kept a close eye on escalating U.S.-China tensions in a thin trading session.

MSCI’s gauge of world stocks gained 0.4%, nearing a 2-1/2 month high.

Only unprecedented stimulus by global central banks has held up world markets in recent weeks.

The index rebounded more than a Reuters poll expected in May, recovering from its worst decline on record in April as a reopening of Europe’s largest economy boosted corporate expectations.

But with financial markets in Singapore, Britain and the United States closed for public holidays on Monday, market moves were relatively small and held within well-worn ranges.

© 2020 Reuters