Royal Bank of Scotland's (RBS) general counsel has resigned to join rival bank Santander UK as director of legal, compliance, regulatory affairs and anti-money laundering.

John Collins' resignation comes after he was appointed as RBS general counsel just 11 months ago, when he replaced Chris Campbell on his retirement.

Collins will serve a notice period and join Santander in 2016.

He previously served as deputy group general counsel for RBS from 2010 to January 2015 before being promoted to the top job.

He started his career at legacy Dentons firm Wilde Sapte before moving to Citi as a legal counsel and then joining Dutch bank ABN Amro, where he was appointed group deputy general counsel.

ABN Amro was acquired by a consortium including RBS in 2008, with Collins becoming RBS general counsel regions in 2008 and general counsel non-core in 2009, before being appointed deputy general counsel in 2010.

It is not yet clear who will replace Collins at RBS.

News of his resignation comes as the bank is currently in the process of finalising its legal panel after launching a review process earlier in the year.

It is understood that primary magic circle advisers Linklaters, Allen & Overy and Clifford Chance as well as Ashurst and Simmons & Simmons have retained their spots on the panel.

Collins is understood to have told firms in a townhall meeting earlier this year that there would be fewer places on the revised panel, with the bank now considering it more important to have better relationships with fewer firms in order to drive more economic value for both the bank and the firms.

The meeting, in which advisers were also understood to have been told RBS expected them to freeze their fees, formed part of the bank's efforts to make this panel review process more transparent and less onerous than previous overhauls.

The review of the roster, which is due to expire in January 2016 after a three-year term, began in July and was expected to last until the fourth quarter of this year. However, Collins' resignation throws the timing of this into question.

In the last panel review in 2012, RBS slashed its adviser roster from 100 firms to around 60 for a three-year term from 1 January 2013.

Other firms appointed in 2012 included Herbert Smith Freehills, Simmons & Simmons, Eversheds, Addleshaw Goddard, Macfarlanes, Travers Smith, Watson Farley & Williams, legacy Squire Sanders, Freshfields, Berwin Leighton Paisner, legacy SJ Berwin and Stephenson Harwood, as well as regional firms such as Burges Salmon, Osborne Clarke and TLT.