ABB Technology Ventures, the investment arm of ABB, has acquired a control stake in Validus DC Systems, a Brookfield, Conn.–based provider of DC power infrastructure equipment for energy-intensive data centers. No financial terms were disclosed. www.abb.com

Exelon Corp. has agreed to acquire Wolf Hollow, a 720mw natural gas-fired power plant in north Texas for $305 million.

Lafarge SA has agreed to sell a package of U.S. assets to Columbian cement maker Cementos Argos SA. The deal is valued at $760 million, and includes cement plans in South Carolina and Alabama. France-based Lafarge is doing the divestiture to help regain its investment-grade credit rating.

TUESDAY, MAY 10

DuPont said today that it will not raise its bid again for Danish food ingredient company Danisco. Its current offer is $6.4 billion, which was a 5% increase over its prior bid. www.dupont.com

MONDAY, MAY 9

Hertz Global Holdings (NYSE: HTZ) has resumed its pursuit of smaller rival Dollar Thrifty (NYSE: DTG), with a $2.1 billion offer. The bid would provide Dollar Thrifty stockholders with $72 per share, or a 3% premium to Friday’s closing price.

Hertz originally agreed to buy Dollar Thrifty in April 2010 for $1.2 billion, but had the offer rejected by Dollar Thrifty shareholders. Avis Budget Group and Hertz then engaged in a game of one-upsmanship, with Hertz raising its offer to around $1.5 billion and Avis offering $1.8 billion. That last Avis bid was accepted, but has not yet been able to receive regulatory approval from the FTC.

Hertz shareholders include The Carlyle Group, Clayton Dubilier & Rice and Merrill Lynch Global Private Equity. www.hertz.com

International Airlines Group, the company formed via the British Airways and Iberia merger, is planning to bid for Air Portugal, according to The Sunday Times. Portugal is required to privatize the air carrier, as part of its EU and IMF bailout.

Broadcom Corp. (Nasdaq: BRCM) has agreed to acquire SC Square Ltd., an Israeli security software maker, for nearly $42 million. www.broadcom.com

Canadian Tire Corp. has offered to acquire Canadian sporting goods retailer Forzani Group Ltd. for C$771 million in cash, or C$26.50 per share. Canadian Tire already holds a 4% stake in Forzani Group.

Elan has agreed to sell its drug delivery unit to Alkermes for $960 million, including $719 million in cash and a 25% stock position in Alkermes (which will be locked up for 6 months). www.alkermes.com

FRIDAY, MAY 6

Vimpelcom (NYSE: VIP) has agreed to acquire a majority stake in New Telephone Company (NTC) from South Korea’s KT Corp. at an enterprise value of $420 million. 

THURSDAY, MAY 5

General Electric has put its railcar leasing business up for sale, according to The Deal. Morgan Stanley is managing the process. www.ge.com