BioScrip Inc. (Nasdaq: BIOS) has agreed to buy Critical Homecare Solutions from Kohlberg & Co. for $343.2 million in cash and stock. The deal also includes the issuance of 3.4 million BioScrip warrants with a $10 exercise price. Critical Homecare Solutions provides home infusion and home health agency services to patients suffering from chronic and acute medical conditions. The company had previously agreed to be acquired for $534 million two years ago by a blank-check acquisition company called MBF Healthcare Acquisition Corp., but the deal was later renegotiated down to $469 million and then mutually-terminated.

Bridgepoint has picked Goldman Sachs and RBS to lead manage a possible IPO for portfolio company Pets at Home, a U.K.-based pet retailer.

Charterhouse Group has agreed to sell Amerifit Brands Inc., a Cromwell, Conn.-based provider of over-the-counter consumer health and wellness products, to Martek Biosciences Corp. (Nasdaq: MATK) for $200 million in cash. Charterhouse originally invested $80 million into Amerifit in 2005.

Clessidra, an Italian private equity firm, has hired RBC to manage a sale of the Prenergy power station—a project that would be Britain’s largest biomass power plant. Construction on the South Wales project is expected to take three years and cost around $650 million.

D.C. Capital Partners agreed to sell intelligence technology company National Interest Security Co. to IBM. No financial terms were disclosed, although Reuters reports that D.C. Capital will take 9x its original $19.6 million investment.

Permira plans to sell its remaining 10.1 percent stake in German mobile phone group Freenet AG, via a share placement managed by Goldman Sachs and UBS.

Platinum Equity has acquired OAO Technology Solutions Inc. from J.F. Lehman & Co. No financial terms were disclosed. OAO is a Greenbelt, Md.-based provider of managed IT solutions and services to Fortune 500 corporations, global outsourcers and government agencies.

Providence Equity Partners has agreed to sell movie theater chain Kerasotes Showplace Theatres to AMC Entertainment Inc. for an undisclosed amount. Kerasotes owns 96 theaters and 973 screens, primarily in the Midwest. AMC is a portfolio company of JPMorgan Partners, Apollo Management, Bain Capital, The Carlyle Group and Spectrum Equity Investors.

ProSiebenSat1, a broadcaster owned by KKR and Permira, reportedly is considering a management buyout offer for its news channel N24.

Richemont, a Swiss luxury goods company, has offered to acquire a majority stake in German eyeglass frames maker Rodenstock, which is controlled by private equity firm Bridgepoint.

Ripplewood Holdings has agreed to sell its 25.5 percent stake in Japan’s Columbia Music Entertainment to Faith Inc. for $27.3 million.

Ryerson Holding Corp., a Chicago-based metals processor, has filed for a $350 million IPO. It plans to trade on the NYSE under ticker symbol RYI. Platinum Equity took Ryerson private in October 2007 for approximately $2 billion.

TDC investors have short-listed investment banks for a public listing in the second or third quarter. The $9 billion Danish telecom operator was bought via a 2005 LBO by Apax Partners, The Blackstone Group, KKR, Permira and Providence Equity Partners.

Travelport, a New York-based travel services company owned by The Blackstone Group, is prepping a $1.78 billion IPO in London.

Unitas Capital has agreed to sell South Korean convenience store chain Buy The Way to local retailer Lotte Group for around $235 million.