The markets opened higher with the Dow rising 47 points to 12,699 as central banks indicated that they would intervene to stabilize global financial markets. Nasdaq gained 11 points to 2848.

On the upside

MHR Fund Management acquired a 13.6% stake in Navistar International (NYSE: NAV).

Billionaire Carlos Slim Helu purchased an 8.4% stake in energy company YPF (NYSE: YPF).

Questcor Pharmaceuticals (NYSE: QCOR) announced commercialization plans for its rheumatology-related indications treatment H.P. Acthar Gel.

On the downside

MicroVision (Nasdaq: MVIS) priced its public offering of 4.2 million units at $2.50 per unit.

US Airway (NYSE: LCC) reported that more than 90% of its flights were on time in April but acquisition target American Airlines reported the most cancellations.

AAR (NYSE: AIR) reported preliminary fourth quarter results that fell short of analyst expectations.

In the broad market, advancing issues outpaced decliners by a margin of more than 2 to 1 on the NYSE and by 9 to 7 on Nasdaq. The Russell 2000 which tracks small cap stocks added a point to 764.