Pride International Inc. (NYSE: PDE) shares rose 16.2 per cent to $39.98, on volume of 15.5 million, thumping its two-million-share daily average, on news that the offshore oil driller will be acquired by Ensco PLC (NYSE: ESV) in a cash-and-stock deal worth $41.60 a share. Ensco shares slid 3.8 percent to $52.35.

Sirius XM Radio Inc. (Nasdaq: SIRI) was active Monday, trading in 18.6 million shares, catching up on a daily average of 52.1 million. Share prices added 1.7 percent to $1.79.

Omega Navigation Enterprises Inc. (Nasdaq: ONAV) lost 6.2 percent Monday to $1.06. Volume was 221,053 shares, nearly four times its normal daily average. ONAV is a provider of global marine transportation services focusing on product tankers.