LONDON, April 16 (Reuters) – A Saudi Arabian investor has bought a 3.3 billion pound ($6.6 billion) stake in Europe’s biggest bank HSBC Holdings in the past two months, and sees the stake as a long-term investment, his spokesman said.

A regulatory filing said Maan al-Sanea owned 360 million HSBC shares, or a 3.1 percent stake, through Singularis Holdings, an investment company based in the Cayman Islands.

Sanea started buying the shares in mid-February, after problems in HSBC’s U.S. mortgage business hit its share price, a spokesman for Singularis told Reuters. He declined to comment whether Sanea would continue buying shares.

Sanea has long-term shareholdings in other big financial firms, including Citigroup, Bank of China and several Middle East firms, the spokesman said.

He is also the man behind Saad Investments, another investment firm based in the Cayman Islands, but that is not linked to Singularis’s purchase of HSBC shares.

By 1300 GMT, HSBC shares were up 1.3 percent to 930 pence, valuing it at 107 billion pounds. Its shares fell as low as 865 pence last month.