Proactive Investors - SSP Group plc (LSE:SSPG) and WH Smith PLC (LON:SMWH) rallied as the rail watchdog stopped short of recommending a full competition inquiry into prices for food and drinks at stations despite these being much higher than elsewhere.
The Office of Rail and Road (ORR) said it is concerned the market has a lack of effective competition, with prices at station outlets around 10% higher than on the high street.
Outlets only change hands rarely, it added, with little competition and most operators having leases rolled over when they come up for renewal.
The ORR added it continues to look into the market and will make recommendations where improvement might be made.
In a statement, the ORR said: "The railway station catering market isn't working as effectively as it should be.
"More competition between companies to operate at stations would bring real benefits to passengers and taxpayers.”
However, the ORR did not recommend the sector to the CMA, stating the best course of action was to "address the problems identified in our capacity as a sectoral regulator".
SSP, which owns UpperCrust, is the largest operator followed by Costa Coffee and WH Smith but there are also many independent operators, the ORR noted.
Shares in SSP edged up 0.6% to 235.8p and WH Smith rose by 1% to 1,324p.