Hong Kong billionaire Li Ka-shing's Hutchison Whampoa conglomerate said today its net profit for 2013 rose by 20% from the previous year, despite challenging global markets.

The group, which owns Three Ireland, said net profit was HK$31.11 billion ($4.01 billion) for the year ended December 31, compared to HK$25.89 billion in 2012.

Profits were fuelled by growth in areas including its port, hotel and property divisions, the company said in a statement filed to the Hong Kong stock exchange.

The group's ports division generated HK$34.12 billion revenue, up 4% compared to last year, while its property and hotel division saw a 22% increase in revenue from 2012.

Revenue from its telecommunications groups grew by 6% in Europe and earnings before interest, tax, depreciation and amortisation grew 38%.

Revenue for the total group grew 4% from the previous year reaching HK$412.933 billion. 

The group was also lifted by strength in its European retail and telecoms businesses.

For the first time, Hutchison Whampoa's operating profits from Europe surpassed the combined profits from its Hong Kong base and mainland China, Dow Jones newswires reported. 

But the group said global economic "uncertainty" had affected markets and geographies which it operates in.

"However, trends in the second half of 2013 generally showed improvement, leading to a constructive outlook for the group's businesses overall in 2014," Li, Asia's richest man, said in the statement.

Li started out in business as a plastic flower-maker but now commands a vast empire through Cheung Kong Holdings and Hutchison Whampoa, with global assets in property, telecoms, utilities, ports and retail.

Three Ireland is in the process of trying to take over O2 Ireland and has said it is prepared to sell radio spectrum and continue a network sharing deal with a rival in order to win EU approval for its $1 billion bid.

Adding O2 will make Hutchison Whampoa Ireland's second biggest mobile operator behind Vodafone.