* German real estate group Adler slumps to record low

* Frankfurt heavyweights trade ex-dividend

* Vestas slides after slashing margin outlook

* Nordic stocks recover from sharp losses

May 2 (Reuters) - European stocks closed lower on Monday, in a session that marked sharp losses after a sudden brief crash, while downbeat China factory data sparked worries of a sharp economic slowdown.

The pan-European STOXX 600 index dropped 1.5%, set to snap a three-day session of gains, with trading volumes thinned by a UK bank holiday.

The STOXX 600 fell as much as 3% earlier in the day, and the Stockholm benchmark stock index shed 8% in what brokers said was a "flash crash" or an erroneous trade.

A gauge of euro zone stocks volatility also saw a sudden spike to hit its highest since mid-March at 35.99. It was last seen at 34.04, while the Stockholm index clawed back losses to trade down 1.6%.

Data released over the weekend showed factory activity in China contracted more than feared in April as widespread COVID-19 lockdowns halted industrial production and disrupted supply chains.

China-linked sectors such as autos, luxury, chipmakers and industrials dragged on the main index.

"While we can expect further supportive measures from Beijing over the coming months, the virus restrictions would likely pose a downside bias to the economic activities," Commerzbank analysts said. "The growth outlook still looks challenging."

Wall Street was mixed on Monday, with the tech-heavy Nasdaq edging higher as growth stocks rebounded after April's rout.

The U.S. Federal Reserve is scheduled to meet this week, with traders betting on a 50-basis-point rate hike to combat rapid inflation.

Worries over China's rigid COVID restrictions, the conflict in Ukraine and expectations of aggressive U.S. monetary policy tightening have stoked concerns of a sharp slowdown in the global economy, pulling the STOXX 600 down 9% on a year-to-date basis.

Further, two senior ministers in Germany backed an immediate European Union ban on Russian oil imports, saying Europe's biggest economy could weather shortages and price hikes.

Ex-dividend factors weighed heavily on the STOXX 600, with automaker Mercedes-Benz, healthcare company Bayer , auto parts maker Continental and chemical group BASF all losing their payout attraction.

Wind turbine maker Vestas dropped 7.9% after it slashed its full-year operating profit margin outlook.

German real estate firm Adler Group SA slumped 29.2% to a record low as it said all members of its board of directors had offered to resign with immediate effect, after an auditor declined to give an opinion on the company's financial statements. (Reporting by Sruthi Shankar and Shreyashi Sanyal in Bengaluru; Editing by Shounak Dasgupta and Shailesh Kuber)