Qatar also has stakes on the Costa Smeralda and Qtar Airways has a 49% stake in Meridina, as well as part of food producer Inalca.
Economic consequences were already emerging, with UAE carriers Emirates, Etihad, flydubai and Air Arabia, as well as Saudi Airlines, announcing the suspension of all flights to and from Qatar as of Tuesday morning.
Saudi Arabia and Iran are at odds over a number of regional issues, including Iran's nuclear program and what Saudis see as Tehran's growing influence in the kingdom's sphere of influence - especially in Syria, Lebanon and neighboring Yemen.
Rabat -Saudi Arabia, Bahrain, the United Arab Emirates, Egypt and now Yemen and Libya have all severed ties with Qatar.
The countries also said they would eject Qatar's diplomats. The Qatar Stock Exchange fell more than 7 percent.
The diplomatic rift could have a serious impact on some business deals and companies in the region, particularly Qatar Airways, which can no longer fly to some of the Middle East's biggest markets.
May's Conservatives send new mixed message on tax as election nears
We're not in the business of punishing people for getting on, on the contrary we want people to keep more of their earnings. Mr Corbyn said he would not make any deals with other parties.
"The campaign of incitement is based on lies that had reached the level of complete fabrications", the Qatari foreign ministry said in a statement.
On May 27, Qatar's ruling emir, Tamim bin Hamad Al Thani, called Iranian President Hasan Rouhani to congratulate him on his re-election.
Speaking in Sydney, US Secretary of State Rex Tillerson said he did not expect the announcement to have "any significant impact, if any impact at all, on the unified fight against terrorism".
And though the comments appeared on Qatar's official website, Qatari authorities said the website has hacked and the comments fabricated.
Last year, Maldives severed its 40-year-old diplomatic ties with Iran, saying the country's policies in the Middle East are detrimental to peace and security in the region. Bahrain says it is cutting diplomatic ties to Qatar amid a deepening rift between Gulf Arab nations.
Qatar is also a member of OPEC, the oil cartel led by Saudi Arabia.
In his Riyadh speech against extremism, Trump singled out Hamas, which rules the Gaza Strip, the Islamic State group, Al-Qaeda, and Lebanon's Hezbollah, which is backed by Iran. Bahrain's foreign ministry said Qatar has destabilized Bahrain, interferes in their affairs, escalates and incites through the media, supports "armed terrorist activities", and has "funding linked to Iran groups to carry out sabotage".
The modest reaction-the FTSE 100 stock index was down 0.2%, compared with a 0.2% dip in the pan-European STOXX 600 index-follows the pattern after attacks in other European cities in recent months.
"We are friends, we've been friends now for a long time, haven't we?"