The shares of Vodafone rose 4% in London on news that activist investor Cevian Capital had acquired a stake in the telecom giant.

ADRs traded on the Nasdaq were up 0.4 %.

According to sources, Cevian has been in talks with Vodafone officials in recent months, pressuring the carrier to improve its performance.

The Swedish investment group has a number of options, according to the article, including pressuring the British firm to concentrate its presence in important regions, sell some companies, or pursue stock buybacks.

File:Vodafone 2017 logo.svg - Wikipedia

The company provides mobile services in the United Kingdom, Germany, Italy, Spain, and Sub-Saharan Africa. It also has a joint venture in India, but due to repeated losses and years of legal challenges that are finally over, the worth of that business was written down to zero more than two years ago.

In November, when the business released its half-year results, Chief Executive Officer Nick Read touted the company's efforts to consolidate in its "important European markets." A major newswire reported this month that Vodafone expressed interest in buying CK Hutchison's Three UK unit late last year. Separately, it has been in talks with Deutsche Telekom about combining their tower businesses.

Cevian, according to the newswire, avoids public conflicts in the first place, preferring to build up a substantial enough stake to force management to listen. It only becomes public if behind-the-scenes lobbying fails to produce the intended result.

Vodafone's total sales increased 5% to 22.5 billion euro ($25.2 billion) in the first half, but profit decreased more than 13% to 1.3 billion euro, owing primarily to a one-time gain the previous year.

Vodafone has joined a growing list of British corporations that have seen an increase in activist investor activity pressing for changes. Shell and GlaxoSmithKline are two others.