Japan's Sumitomo Mitsui Bank has sold about half its stake in Barclays, which it acquired during the financial crisis.
The bank sold 84.5 million of its shares in the UK-based bank at 308.5p, which were worth £260 million ($405 million).
Sumitomo Mitsui Bank purchased 169 million shares in Barclays at 296 pence in June 2008 as part of a series of fundraisings the bank ran during the financial crisis.
As a result of its shares it was Barclay's seventh-biggest shareholder last month, with a stake of about 1.3 per cent.
In a statement Sumitomo Mitsui Bank said it will "continue to maintain a good relationship with Barclays".
Meanwhile, Barclays said its deal with Qatar investors is being investigated by UK and US authorities over some of the commercial agreements between the two sides.
Investors from Qatar, Singapore and China joined Sumitomo Mitsui Bank in buying up shares in Barclays in 2008.
By Asim Shah