LONDON, June 5 (Reuters) - Google parent Alphabet

must face a lawsuit worth up to 13.6 billion pounds

($17.4 billion) for allegedly abusing its dominance in the

online advertising market, London's Competition Appeal Tribunal

(CAT) ruled on Wednesday.

The lawsuit, which seeks damages on behalf of publishers of

websites and apps based in the United Kingdom, is the latest

case to focus on the search giant's business practices.

Ad Tech Collective Action is bringing the claim on behalf of

publishers who say they have suffered losses due to Google's

allegedly anti-competitive behaviour.

Google last month urged the CAT to block the case, which it

argued was incoherent. The company "strongly rejects the

underlying allegations", its lawyers said in court documents.

The CAT said in a written ruling that it would certify the

case to proceed towards a trial, which is unlikely to take place

before the end of 2025.

The tribunal also emphasised the test for certifying a case

under the UK's collective proceedings regime - which is roughly

equivalent to the United States' class action regime - is

relatively low.

Google did not immediately respond to a request for comment.

Ad Tech Collective Action's case comes amid ongoing probes

by regulators into Google's adtech business, including by

Britain's Competition and Markets Authority and the European

Commission.

Google is also fighting two lawsuits in the United States,

one brought by the Department of Justice and another by Texas

and other states, accusing the company of anti-competitive

conduct.

Google's lawyers said in documents for the CAT case that the

company's "impact in the ad tech industry has been hugely

pro-competitive".

Wednesday's decision is the latest against a tech giant to

be given the green light by the CAT, which already this year has

certified a $3.8 billion case against Facebook parent Meta

and a nearly $1 billion case against Apple ( AAPL ).