LOTHIAN Buses are one of the success stories of Scotland's transport system, with the firm emerging out of the the old publicly-owned Lothian Regional Transport and still owned by Edinburgh City Council.

But with its sister company, Edinburgh Trams, mired in controversy because of huge cost overruns, the bus firm could do with steering away from trouble itself.

But that has not been the case. Four directors of the company, now working a lengthy notice period after a boardroom fall-out, have been earning a million pounds in annual salaries between them. And now The Herald reveals that they were accustomed to accepting generous hospitality involving golf trips, dinners and entertainment on a regular basis.

Worse, at least in terms of public perception, among the most regular providers of this largesse was the Swedish car and bus giant Volvo, which went on to win a major share of a contract for new buses.

There is no suggestion of any impropriety in any of this, but it hardly stands out as a beacon of good practice. Four men - their gender is significant in the light of some of their activities - earning between £200,000 and £270,000 a year were happy to accept a range of invitations for corporate hospitality, including in the case of three of them, an annual all-male Transport Golfing Society dinner, with Volvo picking up the bill.

The company seems to be aware that best practice was not being observed, as it has recently change the rules on hospitality, lowering the limit from £300 to £100 for declarations and ordering that no more all-male events be attended.

The four directors accepted 19 offers of hospitality in just over a year. On seven of those occasions it was Volvo who were picking up the tab. When the company came to upgrade its fleet in 2010 of 25 new buses 10 were supplied by Volvo with the rest coming from Falkirk based Alexander Dennis.

The bus company stressed: "It's normal practice in business for directors and senior managers to engage appropriately with suppliers at events.

"Such engagement is covered by our code of conduct which has recently been updated and clearly sets out how relationships are managed to ensure any engagement is transparent, appropriate for the company and recorded in the right way."

We would take particular issue with the use of the word transparent, as this information only came to light as a result of requests under Freedom of Information, and the change in the declaration rules only took place from January this year.

The image of public sector transport chiefs, each earning more than £200,000, being wined and dined by potential suppliers is not an edifying one, whatever the company says about it being normal practice in business.

The confidence of the capital's citizens has already been badly dented by the trams debacle, so the last thing required is for question marks to be raised over the running of a bus company which actually has an inviable reputation for its services.

When a a company is publicly owned it is all the more important that in every possible regard it demonstrates the utmost probity. There are political enemies out there of the whole concept of public ownership and, particularly where a good service is being provided as it is in the case of Edinburgh Buses, every effort must be taken to prevent that reputation being tarnished.