LONDON, June 6 (Reuters) - Amazon ( AMZN ) is facing a

one billion-pound ($1.3 billion) collective lawsuit from British

retailers who allege that the online marketplace misused their

data to boost its own market share and profits.

The British Independent Retailers Association (BIRA), an

umbrella body grouping numerous small traders, was due to file

the lawsuit on behalf of around 35,000 retailers at the

Competition Appeal Tribunal (CAT) in London on Thursday, its

lawyers said.

The suit alleges that Amazon ( AMZN ) made use of non-public data

provided by retailers selling goods on Amazon's ( AMZN ) Marketplace to

offer cheaper rival products for sale directly to consumers.

BIRA Chief Executive Andrew Goodacre said small

retailers had little choice but to use Amazon ( AMZN ), given its reach,

but that the case was intended to stop it putting them out of

business.

"The filing of the claim today is the first step towards

retailers obtaining compensation for what Amazon ( AMZN ) has done,"

Goodacre said in a statement.

Amazon ( AMZN ) did not immediately respond to a request for comment.

BIRA's case also alleges that Amazon ( AMZN ) manipulated the "Buy

Box" feature on its website, shown near the top of product

pages, to its own advantage.

The "Buy Box" is the subject of a separate lawsuit brought

on behalf of consumers and valued at up to 900 million pounds

($1.1 billion).

Britain's Competition and Markets Authority (CMA) said in

2022 that it was investigating Amazon ( AMZN ), including the way it

selects the products placed within the "Buy Box".

Last year, the CMA said it had accepted commitments from

Amazon ( AMZN ) to help protect fair competition on its retail platform.

($1 = 0.7830 pounds)