UPDATE 2-UK stocks end lower on concerns over corporate debt; AstraZeneca weighs

* AstraZeneca slips on report of potential merger with
Gilead

* Plus500 falls after big revenue hit from client trading
wins

* Oil & gas stocks gain after OPEC production cuts

* BP rises after report of job cuts
(Adds details, updates to close)

By Shreyashi Sanyal and Ambar Warrick

June 8 (Reuters) - British stocks ended lower on Monday
after a series of strong sessions as heavyweight AstraZeneca
slipped on a report that it had approached Gilead Sciences for a
merger, while broader concerns over corporate debt also weighed.

The FTSE 100 slipped 0.2% and AstraZeneca
shed 2.7%, serving as the biggest weight on the index. Bloomberg
News reported on Sunday about the British firm's approach for a
possible megamerger with its U.S. rival to form one of
the world's largest drug companies.

The midcap FTSE 250 index fell 0.5%, with financials
among the biggest drags. Healthcare stocks lagged
the broader market, while oil and gas stocks jumped
1.7%, tracking recent gains in crude prices after the OPEC+
extended its production cuts.

An industry body, TheCityUK, has said about a third of the
debt being taken on by British firms under the government's
emergency COVID-19 lending plans could be unsustainable, raising
the need for fresh capital from new investors.

"The lobby group warned that up to 36 billion pounds
($45.67 billion) of recent government-backed loan initiatives
risk turning toxic," said Chris Bailey, European strategist at
Raymond James. "It's not an easy economic recovery to manage,
even assuming no second wave."

British stocks have marked a meaty rise from lows hit in
March, as investors looked to an economic recovery with the
scaling back of novel coronavirus-driven curbs on social and
business activity this month.

BP Plc rose 1% after Reuters reported that the oil
and gas heavyweight will cut about 15% of its workforce in
response to the COVID-19 crisis, which had decimated oil prices.

Plus500 Ltd slid 4.4% after the online trading
platform said its quarterly revenue took a hit from client
trading wins.

Oxford Biomedica climbed 4.8% after the gene and
cell therapy firm said it signed a new manufacturing agreement
to help it scale up production of AstraZeneca's potential
COVID-19 vaccine to cater to demand in the United Kingdom and
Europe.
($1 = 0.7882 pounds)
(Reporting by Shreyashi Sanyal in Bengaluru; Editing by Arun
Koyyur, Uttaresh.V and Ken Ferris)