In a stock exchange statement, 3i announced that Edward Bramson's (pictured) latest vehicle, Sherborne Investors (Guernsey) B Ltd., and its adviser, Jefferies & Co., had been trading in its shares, and that Jefferies' stake had risen to 1.6%, by Jan. 22.

"We believe that Sherborne has acquired and then sold 3i shares to Jefferies," the company said, before reminding shareholders that Sherborne B raised £207 million ($325 million) late last year, "with the stated objective of investing in a company which [...] it considers to be undervalued." It also pointed to a report in early January, which said that most of the money would be used to buy "up to 30% of one target."

The move stirred memories of Bramson's move on F&C Asset Management plc in 2011 when he sacked much of the board, including former 3i boss Brian Larcombe, installed himself as chairman and began a two-year strategic program to turn the firm around. In the meantime, much of F&C's senior management has also been replaced.

It also reminded investors of a campaign by another activist investor, Laxey Partners Ltd., to have 3i sell off its assets in an orderly run-down, before 3i saw Laxey off with a radical diet of its own instigated by CEO Simon Borrows.

But analysts were skeptical Tuesday that Bramson would achieve much at 3i.

"It is not obvious to us where the value lies following a strong run in the share price and an estmateed discount [to net asset value] of 10%, but it will be interesting to see how this unfolds," noted J.P. Morgan Cazenove Ltd. analyst Christopher Brown. "If 3i is [Bramson's] next target, we would just note that he will not be able to acquire much more than a 9% stake," Brown added, apparently referring to the number of 3i shares the investor could buy with an unleveraged £200 million.

Meanwhile, Société Générale Cross Asset Research analysts wrote that Sherborne had already missed the 40% recovery in 3i's stock price, but was perhaps hoping to benefit from further upside as the firm sold off more assets during 2013.

"We find Sherborne's stake building in 3i [...] rather curious," they said, "given that the self-help and turnaround strategy not only started last May with the appointment of Simon Borrows as CEO, but a great many of the measures needed to fix some of 3i's problems have already been addressed."

As well as cutting staff, closing offices in Europe and Asia and reducing debt, 3i has embarked on an ambitious program of asset disposals, putting portfolio companies Scanlines GmbH, Labco SAS, Mold Masters and Civica Group Ltd. up for sale and reportedly also preparing a sale of Hyperion Insurance Group Ltd. It would also benefit from an initial public offering of biopharmaceuticals business Quintiles Transnational Corp., in which 3i and its third-party funds hold about 7%, if larger shareholders TPG Capital and Bain Capital LLC manage to list the business later this year.

Neither Jefferies nor Sherborne immediately replied to requests for comment. 3i will announce its year-end net asset value on Thursday. Its last reported NAV was 273 pence at the end of September, which, according to analysts at Numis Securities Ltd., "implies the stock trades on a far narrower discount of 5% than it has in recent years."

3i shares were up 7.9 pence, or 3.1%, at 266 pence by early afternoon Tuesday, generating a market capitalization of £2.59 billion.