The Business On... Tim O'Toole, COO, FirstGroup

Who he?

O'Toole, from Philadelphia, is the new chief operating officer of FirstGroup, the transport group that runs buses and trains around the UK. With the leading internal candidate for the chief executive's job at FirstGroup, due to come up shortly, announcing her departure yesterday, he looks set for an early promotion.

An American running our buses?

Not just any American. O'Toole knows this isle well, having spent six years running London Underground. He even got a CBE for getting the Tube up and running so quickly after the 7/7 terrorist attacks in 2005.

So, a public-private partnership?

Not really. O'Toole quit London Underground in 2009. Officially, he wanted to go home to his family in America – off the record, friends also said he was fed up with funding shortfalls at LU and the perception that Gordon Brown had broken promises about its finances.

Will he be welcomed back?

Well, not too many people have made friends of both Boris Johnson and the trades unions that represent LU's staff. The Mayor said goodbye to O'Toole 15 months ago by saluting his "huge progress" at the Tube. The unions' tribute was a little different: since he left, they've arranged a string of strikes – his tenure saw barely a day lost to industrial action.

The right man for the job, then?

Could be, but O'Toole is going to have his work cut out sorting out FirstBus's most troublesome franchise, the Thameslink service in and out of King's Cross. The delays on the service, caused by a pay dispute with drivers, got so bad that Lord Adonis, the former transport minister, threatened to take Thameslink off FirstGroup earlier this year.

Sounds like he'll be busy?

A salary even higher than the £450,000 he got for running LU should be a comfort. As will the chance to reconnect with Chelsea, for whom he developed something of a passion during his last stint in the UK. He's also a Frank Pick fan, so at least he'll have the chance to admire Pick's signage at King's Cross when the Thameslink is delayed again.