Cartesian Capital Partners, the boutique set up by two former SVM fund managers in partnership with Ignis Asset Management, is to cut the umbilical cord and become independent.

It marks the end of the joint-venture experiment created in 2005 by Britannic Asset Management chiefs Gavin Stewart and Jonathan Polin, who had plans for a portfolio of 10 fund boutiques and had to stop at three. Britannic became Resolution which became Ignis, now part of Pearl-owned Phoenix, and in a changed investment landscape the three boutiques were effectively cut adrift as Ignis lost interest in marketing its satellite funds.

Now founder Andrew Kelly, whose co-founder David Stevenson left the business last year after a patch of poor performance, has the challenge of going it alone, with partners Susan Rafferty and Jeremy Hall. The recent strong performance of the group's two principal funds under Mr Hall has helped stabilise the Cartesian ship, after it saw assets slip from a peak of £600 million to under £200m, and it is now setting a £1 billion to £2bn target.

"We were the second boutique and Gavin Stewart and 'JP' gave us the opportunity which was fantastic from our point of view," Mr Kelly says. "We have got to a stage where in terms of assets under management we will be a profitable business, and we have quite an extensive track record."

But he admits: "What we have been disappointed by is the lack of asset growth in the past couple of years – Ignis had a strategy of growing their internal funds... we have been a little bit frustrated. We have got sufficient clients to make it a good business but there is a tendency if you don't think about growing your business to end up going backwards."

It will take nine months to complete the amicable separation, as Cartesian, which has only ever known a plug-in to Ignis infrastructure, gradually replaces it. Meanwhile, the focus will remain on keeping clients happy with the house's all-UK focus, Mr Kelly says. "Our strongly-held view is the drift towards global funds is leaving untapped opportunities, and the scope for good fund managers to make a material difference to clients' returns is huge."

Cartesian calls its flagship £65m UK Opportunities fund a "best of British" portfolio. "We are interested in finding companies with outstanding long-term track records, opportunities to dominate their markets, or with powerful and defensible niches in their market. What we don't want to get involved in is businesses in some sort of terminal decline where you are just hoping for a pick-up before it goes off again."

Its £45m Enhanced Alpha fund, which uses "limited shorting", and £27m hedge fund which was at one time over £100m, are both Dublin-based but that is under review, while Mr Kelly says they will "change the fund structures to make them more commercial".

He says: "We don't expect a flood of money straight away, but the important thing is for people to know we are there."