MBIA, AMAG, Sysco, Vitae and National Bank of Greece are big market movers

Stocks that moved substantially or traded heavily Monday on the New York Stock Exchange and the Nasdaq Stock Market:

NYSE

MBIA Inc., down $1.95 to $6.37

The financial guarantee insurance company's shares fell as Puerto Rico's governor warns that the island can't pay its $72 billion public debt.

National Bank of Greece, down 31 cents to 97 cents

The bank's shares tumbled as the Greek government issued banking controls after talks with the nation's creditors break down.

Sysco Corp., down 83 cents to $37.54

The food distribution company is scrapping its proposed $3.5 billion buyout of US Foods because of regulatory opposition.

General Electric Co., down 45 cents to $26.64

The industrial conglomerate and financial-services company is selling its U.S., Mexico, Australia and New Zealand fleet business.

Nasdaq

AMAG Pharmaceuticals Inc., down $3.22 to $67.14

The pharmaceutical company is buying stem cell storage company Cord Blood Registry from private equity firm GTCR for $700 million.

Vitae Pharmaceuticals Inc., down $1.45 to $13.74

The biotechnology company reported disappointing results from an ongoing midstage study of a diabetes treatment.

MYR Group Inc., up $1.73 to $30.96

The electrical construction services company is being added to the S&P SmallCap 600 GICS Construction & Engineering index.

Aratana Therapeutics Inc., up $1.41 to $14.85

The pet therapeutics company reported positive results from a study on a potential appetite stimulation therapy for dogs.