The LME cut fees on short-dated carries in October and on medium-dated carries in November in a bid to revive volumes after total turnover on the exchange fell by 4.3 percent in 2015 and 7.7 percent in 2016.

The LME warned at the time, however, the reductions could be reversed after one year if they failed to revive volumes.

Carry trades are used to link contracts that mature on different dates.

"It's too early to really draw trends but on the data we have available it looks reasonably positive," LME Chief Executive Matt Chamberlain told a briefing.

The LME, owned by Hong Kong Exchanges and Clearing Ltd, released data on Friday showing volumes of short- and medium-dated carries rose by 4 percent and 19 percent respectively in January compared to last year's levels before the fee cuts.

"That medium-dated number is sustainable ... Short-dates carries are more driven by market conditions than by our fees."

The LME compared January's volumes with the average volumes during the months in 2017 leading up to the fee cuts: January to September for short-dated carries and January to October for medium-dated carries as there was a one-month lag between the cuts.

The fee cuts were part of a wider package of reforms that include a new booking fee on over-the-counter trades that bypass the exchange but reference the LME's prices.

Chamberlain said if all parts of the reform were successful the fee cuts would likely be extended.

"As we see volumes hopefully growing through this year, as we bring in new initiatives such as the booking fee, in the aggregate does that get us to the revenue we are looking for?," he said.

"I'm confident that it will. If that does, we'd be confident about being able to extend the (fee) discounts."

Total trading on the LME rose 0.5 percent last year, helped by broader market recovery as industrial metals prices surged to multi-year highs.

Total average daily volumes across all contracts - when adjusted to strip out unallocated trades - were slightly lower in January than last year's average.

Chamberlain said this was largely due to a reduction of volumes coming through incentive schemes for systematic traders.

(Reporting by Peter Hobson. Editing by Jane Merriman and David Evans)

By Peter Hobson