* Compass, Whitbread find horse DNA in beef products
* Sainsbury, Iceland says products horse-free
* FSA to publish results of testing Friday
* Tesco to build new testing system
LONDON, Feb 15 (Reuters) - Compass Group, the world's biggest catering firm, and Whitbread, Britain's biggest hotel group, are the latest companies to be dragged into the growing horsemeat scandal, saying equine DNA was found in products they sold as beef.
The scandal, which has triggered product recalls and damaged confidence in Europe's vast and complex food industry, erupted last month when tests carried out in Ireland revealed that some beef products also contained horsemeat.
It has enraged shoppers and implicated retailers, processors, traders and abattoirs stretching from Ireland and France to Cyprus and Romania.
Compass, which serves 4 billion meals a year, said on Friday it had sold beef burgers distributed by Irish firm Rangeland Foods to a small number of sites in Ireland and Northern Ireland.
Compass' own tests showed those products contained "a minor amount of horse DNA". Those products have now been withdrawn, it said, adding it was now testing all processed meat products and working to establish the details of what happened.
Whitbread, owner of Costa Coffee, pub restaurant chains Beefeater and Brewers Fayre, and hotel chain Premier Inn, said beef burger and lasagne products had tested positive for horse DNA and been withdrawn from sale.
"We are shocked and disappointed at this failure," it said.
Separately, Lancashire County Council in north-west England said it was recalling cottage pies from 47 schools after they tested positive for traces of horse DNA.
Later on Friday Britain's Food Standards Agency will publish the results of DNA testing of more than 1,000 meat products.
J Sainsbury, Britain's No. 3 grocer, and smaller rival Iceland both said on Friday they had not found any traces of horse DNA in their products.
Takeaway hot snack chain Greggs and the JD Wetherspoon pub chain have also reported no horse contamination of products.
British supermarkets, including market leader Tesco and No. 2 Wal-Mart's Asda, as well as fast-food chain Burger King and food manufacturer Findus, have all recalled products sold as beef but which contained horse DNA.
Tesco CEO Phil Clarke said on Friday the firm would build a new traceability and DNA testing system, including a website where customers can view the firm's progress.
He said Tesco had to give consumers "confidence that if it isn't on the label, it isn't in the product."