Aug 15 (Reuters) - Shares in Bahrain's GFH Financial Group GFH.DU fell sharply on Tuesday as the firm said it had acquired $1.2 billion of infrastructure assets in Africa and the Middle East by increasing its capital, diluting minority shareholders.

The financial firm, which did not give details of the assets, said in a bourse statement that it had made the acquisition through a $315 million capital increase, taking GFH's issued and paid-up capital to $975 million.

GFH's Dubai-listed shares GFH.DU sank 3.3 percent to 1.75 dirhams, bringing their losses over two days to 12.9 percent.

Chief executive Hisham al-Rayes told Al Arabiya television that the company had agreed with the sellers of the assets, whom he did not name, to swap them for equity in GFH at 3.5 dirhams per share.

"At the time the deal was made, the estimated fair value of the company was 3.5 dirhams a share," he said without elaborating.

Rayes said some existing shareholders in GFH had increased their holdings in the company through the capital increase, while some financial institutions and wealthy individuals had bought into the company.

Integrated Capital, which was acquired by Shuaa Capital SHUA.DU in July from Abu Dhabi Financial Group, is the largest shareholder in GFH with an 11.88 percent stake, according to the latest exchange data.

(Reporting by Celine Aswad; Editing by Andrew Torchia) ((Celine.Aswad@thomsonreuters.com;))