Ardmore Shipping's largest investor has slashed its position by more than half, as the Irish tanker owner's share price languishes despite record fixtures.

According to Securities and Exchange Commission filings, Russell Investments Group has sold more than 2.2m shares in the New York-listed company, bringing its holding to less than 5%, at 1.5m shares.

Seattle-based Russell Investments became Ardmore's top shareholder in January 2019, taking a 3.1m-share