Cleary Gottlieb Steen & Hamilton and Freshfields Bruckhaus Deringer are among four firms to bag roles on cement giants Lafarge and Holcim's sale of €6.5bn (£4.9bn) worth of assets to Irish building supplies group CRH.

The assets are being sold by Lafarge and Holcim to allay competition concerns as the French and Swiss giants try to gain regulatory approval for their planned merger in the first half of 2015.

CRH said the deal, which is also expected to close in the first six months of this year, would boost its staff ranks by 15,000 across 11 countries, should it be sealed on time.

The Freshfields team acting for Holcim is being led by corporate partners Alan Mason and Olivier Rogivue in Paris. Among the many other Freshfields lawyers assisting across multiple offices is former global corporate head Edward Braham.

Cleary Gottlieb scored the top role advising Lafarge.

Arthur Cox is leading 11 local firms across 12 jurisdictions for longstanding client CRH.

Client partner Padraig O Riordain is heading the team, with managing partner Brian O'Gorman, corporate partner Maura McLaughlin, tax group co-chair Fintan Clancy and intellectual property partner Colin Rooney also taking key roles.

Sullivan & Cromwell is also acting for CRH, as well as Morgan Lewis & Bockius' Brussels office, led by antitrust partner Izzet Sinan.

Sullivan & Cromwell advised CRH on a related €1.6bn (£1.21bn) equity placing earlier this week which will be used to fund the transaction alongside cash and bank facilities.