Maxim Integrated Products (Nasdaq: MIXM) has agreed to acquire Volterra Semiconductor Corp.(Nasdaq: VLTR) for approximately $605 million (including $155m in cash on hand). The $23 per share deal represents a 55% premium to yesterday’s closing price for Volterra shares.www.maximintegrated.com

Mood Media Corp. (TSX: MM), a provider of Muzak background music to stores and restaurants, is expecting final takeover bids next week, according to the WSJ. Offers may come in north of $850 million, with Credit Suisse and Morgan Stanley managing the process. www.moodmedia.com

Sirius XM Radio Inc. (Nasdaq: SIRI) has agreed to acquire the connected vehicle services business of Medford, Mass.-based Agero Inc. for $530 million in cash. www.agero.com

SolarCity (Nasdaq: SCTY) has agreed to acquire Paramount Solar, a Roseville, Calif.-based direct solar energy sales company, for $120 million (most of which is SolarCity stock). www.solarcity.com

Third Point disclosed that it now holds 1.8 million shares in Walt Disney Co. (NYSE: DIS), plus options to acquire another 32,000 shares. It represents less than a 1% stake in the company.www.disney.com

Trian Fund Management has accumulated a $1.3 billion stake in DuPont Co. (NYSE: DD), according to the WSJ. The 21 million shares represent around a 2.2% stake. www.dupont.com

Halyard Capital has sold Columbus, Ohio-based digital ad agency Engauge Marketing to Publicis Groupe (Paris: PUB) for an undisclosed amount. www.engauge.com

IBM (NYSE: IBM) has agreed to acquire Trusteer, a Boston–based provider of software that helps protect organizations against financial fraud and advanced security threats. No financial terms were disclosed, although an Israeli press report puts the price tag at between $800 million and $1 billion. Trusteer had raised around $10 million in VC funding led by U.S. Venture Partners. www.trusteer.com

BenefitFocus Inc., a Charleston, S.C.-based provider of cloud-based benefits software for consumers, employers and brokers, has filed for a $75 million IPO. It plans to trade on the Nasdaq under ticker symbol BNFT, with GoldmanSachs, Deutsche Bank and Jefferies serving as lead underwriters. The company reports a $15 million net loss on $48 million in revenue for the first half of 2013, compared to a $10 million net loss on $39 million in revenue for the year-earlier period. Shareholders include Goldman Sachs (65.95% pre-IPO stake) and Oak Investment Partners (11.45%).www.benefitfocus.com

Chegg Inc., a Santa Clara, Calif.-based online textbook rental company, has filed for a $150 million IPO. It plans to trade on the NYSE under ticker symbol CHGG, with JPMorgan and BoA Merrill Lynch serving as lead underwriters. The company has raised over $190 million in VC funding, from firms like Kleiner Perkins Caufield & Byers (15.1% pre-IPO stake), Gabriel Ventures (13.4%), Ace Ltd. (9.2%), Foundation Capital (8.5%) and Insight Venture Partners (7.6%). www.chegg.com

Third Point Reinsurance, a Bermuda-based specialty property and casualty reinsurer, raised $276 million in its IPO. The company priced 22.1 million shares at $12.50 per share, compared to plans to offer 22.22 million shares at between $12.50 and $14.50 per share. It will trade on the NYSE under ticker symbol TPRE, while J.P. Morgan, Credit Suisse and Morgan Stanley served as co-lead underwriters. Backers include Kelso & Co., Pine Brook Road Partners and Dan Loeb.www.thirdpointre.bm

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