Lloyds of London, the world's oldest insurance market, said Thursday that it will open a new office in Brussels as a result of Britain's decision to leave the European Union.

The plans came amid the release of full-year figures which showed flat pre-tax profits of £2.1 billion on around £29.9 billion in gross written premiums, up from £26.7 billion in 2015. The group's return on capital, however, slipped to 8.1% from 9.1%, the company said. 

"It is important that we are able to provide the market and customers with an effective solution that means business can carry on without interruption when the UK leaves the EU," said CEO Inga Beale. "Brussels met the critical elements of providing a robust regulatory framework in a central European location, and will enable Lloyd's to continue to provide specialist underwriting expertise to our customers."

"I am excited about the opportunities this venture will offer the market by providing that important European access efficiently," she added.

U.K.-based banks, insurance groups and asset managers are set to lose so-called "passporting" rights to offer financial services around the European Union once Britain completes its exit from the bloc in 2019. In an effort to mitigate any restriction to access, firms have been slowing moving towards establishing operations in the EU, with cities such as Frankfurt, Paris and Brussels competing to attract new tenants. 

TheCityUK, a lobby group that advocates for Britain's financial services industry, has moved from demanding full passporting rights in the country's post-Brexit relationship to a stance that calls for "mutual market access" for both regions.

"For the UK-based financial and related professional services industry, the right Brexit deal will be bespoke, underpinned by mutual market access and based on mutual recognition and regulatory cooperation," the group said late Wednesday in response to the government's triggering of the Article 50 exit process. "We have also consistently called for continued access to high quality talent from Europe and beyond, as well as appropriate bridging and adaptation periods as we leave the EU."