Avast Software, a Czech Republic-based developer of anti-virus software, has acquired Jumpshot, an Austin, Texas-based maker of a PC optimization solution. Summit Partners invested $100 million into Avast in 2011 for around a 25% ownership stake. www.avast.com
Crestview Partners has received multiple bids for Birmingham, Mich.-based investment management firm Munder Capital Management, according to Reuters. The deal could be valued at up to $400 million, with bids coming from Blackstone Group/Advent International and Corsair Capital/Flexpoint Ford. www.munder.com
Guardian Media Group has rejected a £470 million offer for a 50.1% stake in Trader Media fromApax Partners, thus setting the stage for an IPO. Apax Partners already holds a minority stake in Trader Media, and its offer would have valued the company at about £1.5 billion.www.tradermediagroup.com
Investcorp has acquired Paper Source Inc., a Chicago-based stationery and greeting-card retailer, from Brentwood Associates. No financial terms were disclosed. www.paper-source.com
Investcorp has acquired a 30% stake in Theeb Rent a Car Co., a Saudi Arabian car rental company. No financial terms were disclosed. www.investcorp.com
Kohlberg Kravis Roberts & Co. and CDH have agreed to invest $140 million over the next 18 months into Modern Dairy, as part of a new joint venture to deliver premium raw milk to Chinese consumers. The two firms last invested in Modern Dairy five years ago, since which the company has gone public in Hong Kong. www.kkr.com
PLH Group Inc., an Irving, Texas-based provider of construction, and maintenance services to the electric power delivery and pipeline industries, has acquired TTR Substations Inc., a Fresno, Calif.–based electrical substation contractor. No financial terms were disclosed. PLH Group is a portfolio company of Energy Capital Partners. www.PLHGroupInc.com
Turnbridge Capital has sponsored an recapitalization of Pipe Pros LLC, a Corpus Christi, Texas-based installer of casing and tubing. No financial terms were disclosed. www.turnbridgecapital.com
Vista Equity Partners has agreed to acquire Greenway Medical Technologies Inc. (NYSE: GWAY), a Carrollton, Ga.-based provider of IT solutions to ambulatory healthcare providers in the U.S. The deal is valued at approximately $644 million, or $20.35 per share in cash. Vista then would merge Greenway with existing portfolio company Vitera Healthcare Solutions. www.greenwaymedical.com
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