A possible criminal investigation into Goldman Sachs sent the markets lower during the midday with the Dow falling 84 points to 11,082. Nasdaq dropped 30 points to 2481.

On the upside

Power-One (Nasdaq: PWER) reversed year ago losses to post a better than expected profit for the first quarter as revenue surged.

Acme Packet (Nasdaq: APKT) reported sharply higher first quarter earnings that surpassed analyst expectations as revenue soared prompting the company to lift its full year outlook.

First quarter earnings for Thoratec (Nasdaq: THOR) more than doubled to top estimates on strong sales.

On the downside

McAfee (NYSE: MFE) blamed charges for lower first quarter earnings that missed estimatesa and warned that second quarter earnings would disappoint.

FBR Capital Markets downgraded Transocean (NYSE: RIG) after a class action lawsuit was filed against the company for the fire on its Deep Horizon rig last week that is now spilling approximately 5,000 barrels of oil into the Gulf of Mexico every day.

Analysts downgraded Goldman Sachs (NYSE: GS) citing the Securities and Exchange Commission's fraud suit and a possible criminal investigation.

In the broad market, declining issues outpaced advancers by a margin of more than 2 to 1 on the NYSE and by nearly 5 to 2 on Nasdaq. The Russell 2000 which tracks small cap stocks plunged 10 points to 727.