By 1910 P&O purchased the Blue Anchor Line, a company that focused on the transportation of general cargo and emigrants from the UK to Australia and of the Australian wool on the return trip. Until this time, P&O had focused on first class passenger trade. This acquisition provided P&O with an interest in every class of passenger traffic.
The course of expansion by take-over picked up the pace. By 1914 Sutherland became the organizer of undisclosed negotiations resulting in the amalgamation of P&O and British India Steam Navigation Company. BI was Britain’s leading shipping company, which had 131 vessels summing up to 598,203 gross registered tons, in comparison with P&O’s 70 ships of 548,654 grt. BI’s routes went well together with those of P&O—it was prevailing in the Persian Gulf, the Indian Ocean and Southeast Asia, but not so much in the west of Suez. There were no adjustments made pertaining to the company name subsequent to the merger, but until the 1950s P&O and BI had a single board of directors.
By this time, after directing P&O for over 40 years, Thomas Sutherland retired and offered the wheel to James Lyle Mackay, Lord Inchcape, chairman of BI. The change at the top corresponded to the occurrence of World War I, during which the merchant fleet had to compete with submarines, torpedoes, mines and air strikes. 100 ships of the P&O fleet had been requested as the year 1914 concluded.