STA Travel, which provides flights, accommodation, tours and expeditions for 2.5 million students and young people each year, has stopped tours taking in elephant rides and Tiger Temple in Thailand, as well as trips to SeaWorld in Orlando and San Diego, which might have appealed to more mainstream travellers.

The company, which has a turnover of more than £800m a year, is reviewing all its provision involving contact with animals to ensure they meet what it believes are the ethical standards demanded by its customers, some of whom had begun questioning current offers.

The company turned to People for the Ethical Treatment of Animals (Peta) for advice and the animal rights group is now likely to turn its sights on other big holiday companies, especially more family-oriented ones. It believes the move by STA, with its 230 branches, including 50 in the UK, is setting an example for the global travel industry and may result in further shifts towards responsible tourism.

Kathryn Kirkpatrick, who became STA's social responsibility programme manager in March, said: "We are constantly assessing our products to make sure they are of a high quality and responsible. We take this seriously and listen carefully to feedback from animal welfare experts, customers and staff. If something isn't up to our standards, we remove it.

"We are very much at the beginning of this journey. It is really important we do it over time, understand what the issues are and work with organisations that really understand those issues."

She added that much of the firm's business involved volunteer and conservation work and educational trips. "We have a responsibility to them to make sure they have a fantastic experience as well. We need to make sure our products are right for them. We will continue to deliver products if they are done in the right way."

Peta is delighted, saying STA is leading the way in "compassionate" tourism. Mimi Bekhechi, the campaign's associate director in the UK, said: "There is no doubt about the profound suffering that orcas and other dolphins endure in captivity, and with all the exciting activities available to travellers today, companies still profiting from the captivity of sentient beings have their days numbered."

Peta says marine parks deprive complex animals such as orcas, that live in close family units and swim up to 100 miles a day, of a natural environment. Elephant rides, it says, are dangerous to humans and cruel to the animals, while big cats become neurotic in captivity.

SeaWorld called STA's decision "disappointing", adding it was unfortunate it had not approached them "so that we could share with them our high standards of care and the rigorous inspection and accreditation process that assures the health and well-being of our animals".

The marine park operator added: "Unfortunately, like most zoological institutions, we are sometimes targeted by animal activist groups that are opposed to the display of animals and too often trade in charges that are completely baseless."

Marine parks have been criticised by animal welfare groups for decades. Later this month, London will see a protest to raise awareness of captive whales and dolphins as part of the worldwide campaign Empty the Tanks.

Earthrace Conservation UK says about 5,500 cetaceans have died in captivity and this is likely to be a considerable underestimate since many countries do not have to record such figures.

The last UK dolphinarium – in Brighton – closed in 1993, but campaigners have warned that present animal welfare legislation does not ban marine parks.