BOSSES at SPT ran up hotel and travel bills totalling £38,000 while on two fact-finding trips.
The sum does not include the cost of expenses incurred during the visits.
A seven-strong team from Strathclyde Partnership for Transport, headed by chief executive Gordon MacLennan, travelled to Canada and Europe to check out companies bidding for lucrative contracts to upgrade the Subway.
The first trip in December involved visits to Canada, Spain and London while the second in February took them to Denmark, Switzerland and Austria.
In 2010, then chief executive Ron Culley quit in the wake of a £120,000 expenses and travel scandal.
However, SPT has defended the decision to send seven employees on the fact-finding missions.
It pointed out the transport body is in the middle of a £288million upgrade of the Subway which will result in state-of-the-art driverless trains.
A spokesman said: "SPT is progressing with an extensive Subway modernisation programme.
"The next stage includes the purchase of a new fleet of trains, a new signalling and control system and platform screen doors to replace an aging system and deliver a more frequent, reliable and flexible service to our customers while driving down maintenance costs.
"It is a huge investment and likely to take up a substantial amount of our £288m overall funding.
"Before we undertake a contract of that magnitude, we need to carry out detailed technical, operational and financial evaluation of the companies tendering for the work and follow a strict European procurement process.
"SPT is at an advanced stage of the procurement of Subway rolling stock and signalling.
"Detailed technical, operational and financial assessment required a number of staff with significant expertise to visit multiple locations recently - at the request of companies bidding.
"That was undertaken over a short period of time but involved very long days and has been extremely beneficial.
"SPT is confident that our findings will save the taxpayer millions of pounds.
"Given the level of investment and future proofing decisions about to be made, it was imperative these visits took place."