The Nasdaq OMX Group Inc. (Nasdaq: NDAQ) has agreed to acquire eSpeed, operator of a fully executable central limit order book for electronic trading in U.S. Treasuries, from BCG Partners (Nasdaq: BGCP). The deal is valued at $750 million in cash, plus certain contingent issuances of stock that approximate certain tax benefits to NASDAQ OMX. www.nasdaq.com

Aquilex, a portfolio company of Centerbridge Partners, has sold its Specialty Repair and Overhaul business to AZZ Inc. (NYSE: AZZ). No financial terms were disclosed. www.azz.com

Attune Consulting, a global provider to solutions to the fashion and lifestyle industries with a U.S. office in Burlington, Mass., has raised $20 million from Sri Lankan apparel maker MAS Holdings. www.attuneconsulting.com

Carl Icahn has acquired a 9.27% stake in speech recognition software company Nuance Communications (Nasdaq: NUAN), according to a regulatory filing. www.nuance.com

ConnectSolutions, a San Francisco-based private cloud service provider of unified-communications-as-a-service solutions for large enterprise and government organizations, has acquired NextUC, a provider of Microsoft Lync-based UC solutions for streamlining SME communications. No financial terms were disclosed. ConnectSolutions recently raised $10 million in VC funding from Frontier Capital. www.connectsolutions.com

Hess Corp. (NYSE: HES) has agreed to sell its Russian subsidiary Samara-Nafta to Lukoil for approximately $2.05 billion. www.hess.com

Perrigo Co. (Nasdaq: PRGO) has acquired Velcera Inc., a Yardley, Penn.-based pet health products company, for approximately $160 million in cash. www.perrigo.com

Sign up for my daily email newsletter on deals and deal-makers: GetTermSheet.com