UPDATE 2-Autos, miners keep European shares in the red as trade jitters resurface

* Shell Q3 profit falls 15%, shares down

* China doubts long-term trade deal with Trump

* STOXX 600 logs second straight monthly gain
(Updates to close, adds comments)

By Shreyashi Sanyal and Agamoni Ghosh

Oct 31 (Reuters) - European shares fell on Thursday, hurt by
losses for miners and automakers as doubts grew over the
prospect of a trade deal between the United States and China,
with weak earnings from oil major Royal Dutch Shell adding to
the gloom.

A Bloomberg report said that China is doubtful of a
long-term trade deal with U.S. President Donald Trump, raising
fresh uncertainty about progress between the two countries after
an interim trade deal was almost finalised.

The report dashed optimism earlier in the session sparked by
the U.S. Federal Reserve lowering borrowing costs for the third
time this year on Wednesday.

The pan-European STOXX 600 index ended 0.5% lower
but logged its second straight monthly gain after an October
packed with corporate earnings reports along with some Brexit
and trade twists.

"The pain inflicted by the trade war on the U.S. economy may
eventually make it more willing to compromise but the question
is how much pain is needed for a full deal to be signed," said
Timme Spakman, economist, international trade analysis at ING.

Tariff-exposed miners were down 1.4%, while
automakers lost 1.3%.

However, the biggest decliners were oil and gas producers
, which fell 1.7% after heavyweight Royal Dutch Shell
slid 4%.

Shell warned uncertain economic conditions could slow its
$25 billion share buyback plan. That followed warnings from BP
and France's Total earlier this week about
lower oil and gas prices hitting margins.

Airlines also posted some disappointing numbers.

Air France-KLM fell 1% after it said slowing
travel demand was likely to hurt ticket sales in the remainder
of the year, while British Airways owner IAG said
industrial action by pilots at the airline had knocked
third-quarter profits.

In the auto sector, a deal between Fiat Chrysler
and Peugeot owner PSA to create the world's
fourth-largest automaker lifted the shares of Fiat Chrysler
8.2%.

However, PSA fell about 13%, after having risen nearly 5% in
the last three sessions in the run-up to the deal.

Spanish utility Enagas jumped 5.5% after a media
report said a Spanish regulator was considering softening
proposed cuts to gas grid returns.
(Reporting by Shreyashi Sanyal in Bengaluru; Additional
reporting by Agamoni Ghosh; editing by Patrick Graham, Arun
Koyyur, Kirsten Donovan)