First look... Stock futures are down sharply this morning, following selloffs in Asia and Europe, as concerns mount about the sustainability of an economic rebound. World stock markets mostly fell Tuesday amid renewed concerns about the banking sector after Britain's Royal Bank of Scotland PLC got more government help and Switzerland's UBS AG booked another massive charge. Uncertainty about a raft of key economic developments later this week, which culminates in Friday's closely watched U.S. nonfarm payrolls report for October, kept a lid on sentiment as well. Eight of ten reporting Asian/pacific markets are down. The India BSE 30 is down 3.09%. The China Shanghai Composite is up 1.22%. All eight reporting European markets are down. The Austria ATX is down 2.95%. The Australian All Ordinaries is down 0.14%. The highest volume US stocks on the Frankfurt exchange are mixed. E Trade (ETFC), Motorola (MOT), Advanced Micro Devices (AMD), Bank of America (BAC) and General Electric (GE) are up. Ford (F), Alcoa (AA), Intel (INTC) and Citigroup (C) are down.