International companies trading in New York closed plunged Monday as a U.S. sovereign debt downgrade further sapped confidence in the global economy.

The Bank of New York index of ADRs fell 7.3% to 117.77.

Investors fled from risk in the first trading session since Standard & Poor's Ratings Services downgraded the U.S. to double-A-plus from triple-A late Friday. Meanwhile, worries about the global economy loomed large. Investors were underwhelmed by the European Central Bank's move to buy Italian and Spanish bonds. European banks were among the biggest decliners.

Royal Bank of Scotland Group PLC (RBS, RBS.LN) fell 16% to $8.30 as stock-investment downgrades by some analysts also weighed on the shares after the company reported a large first-half loss Friday. ING Groep NV (ING, INGA.AE) tumbled 14% to $8.21. Societe Generale SA (SCGLY, GLE.FR) fell 17% to $6.73, while Barclays PLC (BCS, BARC.LN) retreated 13% to $10.84.

The European index fell 7.4% to 107.63.

The Asian index dropped 6.6% to 118.53.

JA Solar Holdings Co. (JASO) said it expects its second-quarter gross margin to be lower than expected on falling selling prices and the impact of high-cost inventory provisions. Its second-quarter earnings call is scheduled for Aug. 18. Shares slid 17% to $3.35. Peers ReneSola Ltd. (SOL) traded 18% lower to $2.76 while China Sunergy Co. (CSUN) dropped 16% to $1.12.

The Latin American index 9% to 323.77.

Chilean flagship carrier LAN Airlines SA (LFL, LAN.SN) again lowered its estimate for passenger traffic growth as international fuel prices and ash from a volcano in southern Chile grounded many of its flights, daily newspaper El Mercurio reported. Shares fell 11% to $21.76.

Petrobas Petroleo Brasileiro (PBR, PETR4.BR) fell 10% to $26.15. The CEO of the state-run company also known as Petrobras said the impact it will feel from S&P's downgrade of the U.S. is hard to discern.

The emerging markets index dropped 8% to 275.37.

TV panel maker LG Display's (LPL, 034220.SE) shares plunged 14% to $9.54 amid a broad selloff of South Korean companies' shares that MiraeAsset Securities Analyst Lee Jin-woo attributed to "panic mode" sentiment. KG Financial Group Inc. (KB, 105560.SE) dropped 12% to $38.72. Korea Electric Power Corp. (KEP, 015760.SE) retreated 10% to $9.85.

-By Matt Jarzemsky, Dow Jones Newswires; 212-416-2240; matthew.jarzemsky@dowjones.com