Aug 3 (Reuters) - Nickel tumbled on Monday, lagging other

base metals after Indonesia resumed exports of minerals

containing rare-earth by-products, easing near-term supply

concerns.

Three-month nickel on the London Metal Exchange fell

1.56% to $16,980 a metric ton as of 0330 GMT, while the

most-traded nickel contract on the Shanghai Futures

Exchange dropped 1.91% to 129,520 yuan ($19,179.34) a ton.

Indonesia's mandatory rare-earth testing delayed exports of

nickel pig iron and mixed hydroxide precipitate, as well as

bauxite, alumina and copper cathodes.

Presidential Chief of Staff Dudung Abdurachman said on Monday

that the ban applied only when rare earths were the primary

product, and that more than a hundred delayed vessels had now

been able to sail. State surveyor will soon issue 85 previously

delayed reports, he added.

Traders and exporters said the clarification reduced fears

of a prolonged disruption to Indonesian nickel shipments, though

officials have yet to finalise concentration limits and testing

procedures.

Elsewhere, Weaker-than-expected Chinese manufacturing data

added pressure by reinforcing concerns about metals demand in

the world's largest consumer.

The private RatingDog manufacturing purchasing managers' index

fell to 50.9 in July from 51.7 in June, below

analysts' consensus forecast of 51.5 and marking the slowest

expansion in four months.

Growth in new orders slowed to its weakest since January,

while manufacturers cut purchasing activity for the first time

since November.

An official survey released on Friday showed factory

activity unexpectedly contracted in July, adding to concerns

about weak domestic demand and slowing economic growth.

Elsewhere on the LME, copper gained 0,23%, aluminium

dipped 0.09%, zinc rose 0.70%, lead was

little changed, down only 0.03%, and tin ticked 0.12%

lower.

Among other base metals on SHFE, copper nudged

0.13% higher, aluminium dropped 0.40%, zinc

rose 1.02%, lead tumbled 1.25%, and tin gained

0.36%.

($1 = 6.7531 Chinese yuan renminbi)