Slaughter and May has lined up alongside a raft of Danish firms on a €500m (£390m) deal that saw Lego billionaire Kirk Kristiansen team up with a pension fund to secure a stake in Danish facilities giant ISS.

Slaughters took a role advising ISS and majority shareholders GS Capital Partners and EQT Partners as Canadian pension fund Ontario Teachers' Pension Plan (OTPP) and Kirkbi Invest – a holding company that invests on behalf of the family behind Lego – took a 26% stake in the company.

The Slaughters team included corporate partner David Wittmann and senior partner Chris Saul. Danish firm Gorrissen Federspiel advised on Danish elements of the deal, with a team led by partner Tobias Linde.

Meanwhile, local firm Bech-Bruun assisted OTPP, fielding business transfers partner Jakob Kristensen and finance partner Steen Jensen. Danish firm Plesner, whose team was led by M&A partner Thomas Laursen, was instructed by Kirkbi Invest.

The transaction follows UK security group G4S's highly publicised failure to buy ISS after making a £5.2bn takeover bid for the facilities outsourcing firm last year, which fell through after shareholders refused to support the deal.

Slaughters had the lead role for ISS and its owners on the collapsed deal, while Herbert Smith and Norton Rose acted for G4S.

Earlier in 2011 ISS had been forced to abandon a planned $2.8bn (£1.8bn) initial public offering (IPO) amid market volatility, after facing an $8.5bn (£5.5bn) takeover bid from Apax Partners at the end of 2010.

That aborted deal saw Skadden Arps Slate Meagher & Flom and Simpson Thacher & Bartlett in lead roles for Apax Partners, while Gorrissen Federspiel advised on the abandoned IPO.

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