Parcels delivery firm TNT Express is set for a takeover by rival FedEx after the Dutch firm backed an offer worth 4.4 billion euro (£3.2 billion).
The two companies want to combine TNT's European road operations and FedEx's strength in other regions such as North America and Asia.
TNT Express employs more than 65,000 people and has 2,300 depots, with about 8,500 staff employed in the UK at headquarters at Atherstone in Warwickshire and at 54 depots across the country.
It is the second time in recent years that TNT Express has been a takeover target for a US firm after UPS attempted a deal in 2012.
However, the Atlanta-based company ditched its plans when it became clear European regulators were ready to block the move.
Royal Mail shares rose by 2% today as a result of the latest consolidation moves in the European parcels sector.
TNT dates back to 1946 when Ken Thomas started his own transport business in Australia with one truck. In the 1950s Thomas Nationwide Transport developed overnight services before international expansion led to it becoming Dutch-owned in 1996.
TNT Express was created in 2011 following its separation from TNT Post. The business now operates 26,000 road vehicles and 47 aircraft.
However, he added: "While we did not solicit an acquisition, we truly believe that FedEx's proposal, both from a financial and a non-financial view, is good news for all stakeholders."