Marathon Oil, Corning rise; Juniper Networks and Alcoa dip

The computer network equipment maker cut its quarterly projections because of weaker demand from some businesses and project delays from telecommunications customers.

Market research firm IDC said personal computer sales continued to slump in the first quarter, and Dell surpassed HP in sales.

A Deutsche Bank analyst downgraded the coffee chain's stock to "Hold," saying it's trading at a fair price and investor expectations are high.