Rail and bus firm FirstGroup has seen shares tumble after its private equity suitor, Apollo Management, walked away from making a bid for the transport giant.
Shares in FirstGroup - which runs rail franchises including South Western Railway and owns Greyhound buses in the US - plunged as much as 13% after Apollo said it did not intend to make an offer.
Its approach - for an undisclosed amount - was rejected last month by FirstGroup, which said it "fundamentally undervalues the company and is opportunistic in nature".
Apollo had until 5pm on Wednesday to make a firm offer or walk away.
Apollo's interest in the firm was opposed by the Rail, Maritime and Transport union (RMT) as well as the Labour Party.
It comes as takeovers face intense scrutiny following Melrose's controversial buyout of engineer GKN.
But FirstGroup has also come under pressure over its performance and structure, with activist investor West Face Capital pressing for operational changes.
West Face owns a stake in FirstGroup and has raised concerns that FirstGroup's stock is currently undervalued.
While investors showed their disappointment as hopes of a takeover battle were dashed, transport analyst Gerald Khoo, at Liberum, said the approach "highlighted the potential value that lies within FirstGroup".
He added: "We expect management to come under greater pressure to find alternative ways to crystallise value besides its current organic turnaround strategy."
In February, FirstGroup reported a 10.7% rise in year-to-date revenue, though, when stripped of currency effects and excluding the South Western Railway franchise, that increase was just 1.1%.
It said all three of its North American divisions struggled with "extremely challenging" weather conditions in January, while its Greyhound bus long-haul business was hit by intensifying competition with low-cost airlines.