Newcastle-based Watson Burton is set to launch a new office in London within the next six months.
The City office will focus on property, construction and insurance work and will be the first presence in the capital for a North East firm.
Senior partner Andrew Hoyle said: "We've gone there primarily to win more quality work from our existing clients, but also to win more quality clients.
"The rationale for setting up the office is based on existing opportunities in our client base, but we have ambitious plans for growth."
Hoyle confirmed that the London base will open with an initial team of eight, comprising construction partners Rob Langley, Roddy Gordon and Mark Lawton from Newcastle, plus professional indemnity partner Karen Eckstein from Leeds and four full-time associates.
Hoyle added that he is looking to hire down south and said interested lawyers should "absolutely get in touch".
The firm opened its first office outside Newcastle, the 10-partner, 40-staff Leeds office, in May 2005.
The firm is considering two locations for the London move, both in the Bank district of the City. Hoyle said the premises will allow flexibility for growth in numbers, but he cautioned against excessive ambition in the capital.
"We'll try to remain niche until we've achieved success," he said. "We don't want to repeat the mistakes of others."