Clifford Chance (CC) and Slaughter and May have won advisory roles as the UK's competition watchdog raises concerns over MasterCard's proposed £700m takeover of UK payments company VocaLink.

CC is advising MasterCard in connection with the CMA investigation, with a team led by London competition partner Greg Olsen.

Slaughters is acting for VocaLink on the matter, with City competition partner Lisa Wright and London special adviser Jackie Holland taking the lead.

The Competition and Markets Authority (CMA) said yesterday that it has given MasterCard a week to address its concerns that the takeover would harm the competitiveness of the Link system that runs many of the UK's automatic teller machines (ATMs).

It said that VocaLink and MasterCard are "two of the three most credible providers of infrastructure services to the Link ATM network", adding that as a result, the merger would limit Link's negotiating power with those companies and reduce the number of bidders.

MasterCard and Vocalink have until 11 January to offer remedies to address the competition concerns raised, otherwise the CMA could undertake an in-depth investigation into the merger.

A MasterCard spokesperson said: "In its announcement, the CMA noted that it has no concerns related to providing payment infrastructure services to BACS or the Faster Payments Service. We're pleased to have the opportunity to address their one concern, regarding the Link ATM scheme, in the timeframe provided."

The deal was first announced in July 2016, with MasterCard agreeing to acquire 92% of Vocalink for about £700m.

VocaLink is owned by a group of 18 banks and building societies. These include Lloyds Banking Group, Barclays, HSBC, Royal Bank of Scotland and Santander.

Slaughters is acting for the company on the proposed merger with MasterCard with a team led by London corporate partner Rebecca Cousin, alongside M&A head Roland Turnill.

Davis Polk is leading on the corporate aspects of the merger for MasterCard. Its team is being led by London corporate partner Will Pearce, and also includes New York corporate partners Jeffrey Crandall and Pritesh Shah.