Alliance Trust has completed the restructuring of its £2.5 billion portfolio and now holds just 100 stocks, half the number it held earlier this year.

For the first time since the mid-1980s, the biggest holding in the Dundee-based trust, which dates back to 1888, is an overseas company, Pfizer.

The Swiss pharmaceutical giant now accounts for 2.6% of total assets, just ahead of Royal Dutch Shell, which was at 2.4% at the end of October.

Next come Qualcomm, (US technology), Samsung, and Enterprise Products (US energy).

GlaxoSmithKline and Diageo are the only other UK companies in Alliance's top 10 holdings.

The top 20 holdings have seen 11 newcomers since June and increased their share of the portfolio from 30% to 32% in October alone, which Alliance said was "evidence of the desire to increase the level of conviction the trust has in each of its investments".

Information technology has seen the biggest increase in exposure – though seventh-largest holding Apple will have seen its value decline of late.

Ilario Di Bon, chief investment officer, said: "The recent dynamic restructuring of the portfolio has resulted in a significant change at the top.

"With the UK market set to be muted at best during 2013 we are looking further afield and are finding stock-specific opportunities which accord with our long-term thematic investment approach.

"More than half the holdings now in the top 20 investments are listed outside the UK as we invest in high-quality stocks which will continue to perform during the economic cycle."

The restructuring was unveiled only three months ago by chief executive Katherine Garrett-Cox, as the trust closed three funds in its unit trust subsidiary and merged its regional equity portfolios into one global portfolio under Mr Di Bon.

Ms Garrett-Cox said the trust had comprised 450 stocks when she joined Alliance five years ago.