LONDON (Reuters) - Standard Chartered STAN.L will need to spend around $20 million making Frankfurt its European base in order to secure market access to the European Union when Britain leaves the bloc, Chief Executive Bill Winters told Reuters.

A logo of Standard Chartered is displayed at its main branch in Hong Kong, China August 1, 2017. REUTERS/Bobby Yip

Global banks have started enacting contingency plans to ensure they can still serve EU clients after Britain leaves in March 2019 and the cost of those plans has begun to emerge.

Emerging markets-focused lender Standard Chartered said in May that it was in talks with regulators about making Frankfurt its European base, where it already has a branch from which it conducts euro clearing activities.

“It will cost us $20 million probably,” Winters said of the associated costs of converting that branch to a subsidiary.

“Capital won’t go in until you activate the subsidiary, so let’s say March 2019 and that amount is purely dependent on Bafin (Germany’s banking regulator), but would probably be in the hundreds of millions.”

Standard Chartered currently has around 100 staff in Frankfurt and has office space capacity to add another 20.

“One question is where can people sit after Brexit?” Winters in an interview with Reuters.

“It would be costly to physically move all your people who deal with a European client. Basic sales staff and relationship managers are already in situ across the continent.”

HSBC said this week it could spend up to $300 million moving up to 1,000 jobs and parts of its business to Paris following Britain’s exit from the European Union, as well as associated legal fees.

RBS RBS.L also said on Friday it was in discussions with the Dutch central bank to use the Netherlands as its trading base post-Brexit and that set-up costs would be in the low tens of millions.

Winters said the bank also considered Dublin as its EU base and that it was “a very close call” but one of the deciding factors was Ireland’s credit rating, which is below German’s AAA status.

“It would’ve been easy to set up there (Dublin) also. But at the end of day it involved an interesting issue around the country’s credit rating. We felt large institutional investors would prefer Germany.”

The country’s credit rating caps that of any bank subsidiaries operating in it, meaning if Ireland’s rating fell, Standard Chartered’s business there could become more expensive or risky for counterparties to deal with.