Cerberus Capital Management won a big legal victory on Friday when a Delaware court ruled that the US private equity firm was not obliged to close the $6.6bn takeover of United Rentals, an equipment leasing company.

Cerberus walked away from the deal in the wake of the credit squeeze, claiming it had the right to scrap the agreement as long as it was willing to pay a $100m break-up fee. But United Rentals believed that it had a right to “specific performance”, which would have required Cerberus to close the transaction against its will.