Sullivan & Cromwell and Norton Rose Fulbright are among a host of firms scoring roles on Spanish energy giant Repsol’s $8.3bn (£5.3bn) acquisition of Calgary’s Talisman Energy.

The deal will propel Repsol into the top 15 largest privately-owned oil and gas companies globally, according to the company. The deal value excludes assumed debt of $4.7bn (£3bn).