UPDATE 3-Britain bans betting on credit cards to fight gambling addiction

* Ban follows government review launched last year

* 22% of online gamblers are 'problem gamblers' - commission

* Betting companies' shares fall

* PaddyPower owner, Canada's Stars Group likely hardest hit
(Adding graphic, details on market share)

By Kate Holton and Elizabeth Howcroft

LONDON, Jan 14 (Reuters) - Britons will no longer be able to
use credit cards to place bets under the latest move by the
government to tackle problem gambling, hurting the owner of
PaddyPower Betfair and its takeover partner Canada's Stars Group
.

Less than a year after Britain slashed the maximum stake
that can be placed on popular fixed-odds betting terminals, it
said on Tuesday it would ban the country's 24 million gamblers
from using credit cards to bet online or offline to rack up
debt.

According to trade body UK Finance, around 800,000 Britons
use credit cards to gamble. The Gambling Commission believes a
quarter of those are problem gamblers - people who are addicted
to gambling to try to win back their losses.

Shares of betting companies including 888 Holdings,
Flutter Entertainment, the owner of Paddy Power
Betfair and William Hill dropped between 0.9% and 2.5%.

Culture Minister Helen Whately said there was clear evidence
of harm from consumers betting with money they don't have.

"We will not hesitate to take any further action necessary
to protect people from gambling harm," she said in a statement.

Britain has a thriving gambling industry. It employs more
than 100,000 people and made 14.4 billion pounds ($18.7 billion)
after paying out winnings in the 2018-2019 financial year.

But the government has sought to tighten rules in recent
years by capping the maximum stake on terminals, bringing in
stricter age and identity checks for online gambling and
expanding support for those who become addicted.

The new ban will come into effect on April 14 and apply to
all online and offline gambling products apart from
over-the-counter lottery tickets.

The move would likely hurt Flutter Entertainment
the most - it will have under just a third of the UK online
gambling and gaming market once it buys Toronto-listed Poker
Stars operator Stars Group Inc (TSG), according to data from H2
Gambling Capital.

The online industry was worth an estimated 4.4 billion
pounds in revenue in 2018, according to H2.

Davy Research analysts though said the ban would likely lead
to a low single digit percentage drop in related revenues.

"The latest in a recent series of more onerous regulatory
changes, it also acts as a further reminder that the UK
opportunity is no longer what it once was," it said in a note to
clients. "However, it remains a very large, (still) growing and
highly cash generative market for online gaming operators."

Britons had a total of 72.1 billion pounds outstanding on
credit cards in November, according to Bank of England data,
down a little from a record 72.9 billion pounds struck in May.

($1 = 0.7689 pounds)

(Reporting by Kate Holton, Elizabeth Howcroft and Josephine
Mason; editing by Mark Potter)