Colin McLean, founder of Edinburgh's SVM Asset Management, is battling to restore investor confidence in his boutique's biggest fund and head off a potential takeover.

Investment guru Mr McLean is in London for a second day of meetings with shareholders in the SVM Global investment trust, the £130 million fund which began with the company 21 years ago and accounts for a valuable chunk of SVM's £500m under management.

Earlier this month activist investor MAM Funds grabbed an opportunist 7.38% stake in the trust, immediately after SVM had announced the resignation of Donald Robertson, the long-serving director who had co-managed the fund with Mr McLean and held 123,000 shares in the business.

The potentially unwelcome attentions of MAM follow last year's attack on the house's other original investment trust, SVM UK Active, which ended in US investment group Cyrun mopping up 42% of the shares and prizing the £60m fund away from Edinburgh.

Stephen Peters, investment trust analyst at Charles Stanley, commented: "SVM Global is a big part of the company's assets and it is in his [Mr McLean's] interest to keep that fund.

"But activists do have a role, that fund has struggled, and struggling funds do tend to attract interest – now Colin has got to pick it up and convince shareholders to stick with him."

Mr Peters noted that the SVM Global board had written down the value of the trust's assets by 10%, which ought to help future performance.

Mr McLean has already moved to revamp the mandate of the trust, which invests in specialist funds often in illiquid asset classes, and has promised investors an improved performance.

He has also shaken up the group's only other investment trust, the £3m UK Emerging formerly run by Mr Robertson, selling half the stocks in the portfolio.

SVM also runs eight open-ended funds but has now put two of them, the £3m Cautious Managed formerly run by Mr Robertson and the £2m UK Absolute Alpha run by Mr McLean himself, "under review".

SVM Global's asset value was down 14% in the year to August 31, while the world index rose by 7%, it is up 2.7% over three years against 20% for the index, and down 29% over five years, while the index rose by 5.3%.

The £14m SVM Global Opportunities open-ended fund, also managed by Mr Robertson, is down by 36% over three years against an average positive return of 13% for the global fund sector.

SVM's two other big funds have been strong performers. Co-founder Margaret Lawson's £47m UK Growth fund has outperformed the sector across one, three and five years, while Neil Veitch has beaten the sector over one and three years with his £81m UK Opportunities fund.