Continental, UAL shares lower as deal is put off

The surprise move came after weeks of growing speculation that it would join with UAL Corp.'s United Airlines to create the world's biggest airline.

Shares of Continental fell 4.2 percent to $16.48 while shares of UAL declined 6.6 percent to $14.20.

Wm. Wrigley Jr. Co. shares jumped after the candy maker agreed to sell itself to rival Mars Inc. in an all-cash deal valued at $23 billion. Wrigley shares gained 24 percent to $77.30 after closing at $62.45 on Friday.

Visa Inc. shares rose 2.2 percent to $76.80 after several analysts began coverage of the company with positive ratings ahead of the credit card company's first quarterly earnings report since its initial public offering.

Humana Inc. posted better-than-expected results for the first quarter and shares rose 77 cents after closing at $45.65 Friday. Quarterly results have been mixed so far for health insurers. UnitedHealth and WellPoint issued disappointing earnings last week while Aetna topped expectations amid concerns of rising costs and declining corporate membership.