Seattle-based conglomerate Saltchuk Resources appears to be making a run at control of Overseas Shipholding Group (OSG), the venerable operator of US-flag tankers and barges.

Saltchuk, which controls US-flag owner TOTE Maritime, revealed in public securities filings that it bought 11.4m shares of OSG, or 13.3%, between 21 January and 9 March for about $26m, including broker commissions.

The buys, which included two large block purchases of 4.7m