Image copyright AFP/Getty Image caption Dell was taken private in 2013 by its founder Michael Dell and private equity firm Silver Lake

Japan's NTT Data is buying Dell's technology services business for more than $3bn (£2.1bn) as it seeks to expand its business in North America.

This is set to be the biggest-ever acquisition by NTT Data, which is part of Japan's former telephone monopoly.

Dell has reportedly been looking to sell off non-core assets to raise billions of dollars ahead of its $67bn takeover of data storage firm EMC Corp.

NTT Data will take on Dell's 28,000 employees in North America and India.

In a filing to the Tokyo Stock Exchange, NTT Data said the purchase will enhance its cloud and business-process outsourcing (BPO) services.

The firm has been looking for new sources of revenues outside of Japan, which faces a shrinking and rapidly ageing population.

According to Bloomberg data, NTT Data has spent more than 72bn yen buying mostly overseas companies since 2011.

Its main rivals include India's Tata Consultancy Services, France's Atos and US firm Cognizant Technology Solutions.