Monday's market movers

NEW YORK (CNNMoney.com) -- The following are some of Monday's most actively traded stocks:

Alcoa (up $2.32 to $37.98, Charts, Fortune 500) announced it was making a $33 billion cash and stock bid for Canadian rival Alcan.

ABN AMRO (down $0.91 to $48.99, Charts) rejected a bid by Royal Bank of Scotland for its U.S. LaSalle unit.

Armor Holdings (up $4.38 to $86.53, Charts) said before the bell it will be acquired by British defense company BAE Systems for $88 per share, or $4.1 billion.

Alcan (up $20.05 to $81.08, Charts) received a cash and stock bid at a major premium to its Friday closing price from Alcoa.

American Tower (up $0.85 to $39.26, Charts) reported a profit of 5 cents per share for the first quarter, compared to a year-ago loss of one cent per share.

Dominion Homes (down $0.03 to $5.57, Charts) reported a loss of $1.41 a share, compared to a loss of 63 cents per share in the year-ago quarter.

Hansen (down $1.22 to $38.10, Charts) reported that its margins declined to 51.5 percent in the most recent quarter.

Johnson & Johnson (down $0.51 to $63.97, Charts, Fortune 500) said its experimental drug-coated stent failed to meet its primary study goal, leading it to drop development of the heart device.

Onlookers said that Magna International (up $0.35 to $78.97, Charts) is the only party interested in making a bid for struggling auto maker Chrysler.