MUMBAI, Dec 7 (Reuters) - A leading Indian trade body on Thursday suggested that the Group of Seven countries should offer greater flexibility in implementing a ban on indirect imports of Russian gems and provide specific details regarding the ban's implementation.

The G7 on Wednesday announced a direct ban on Russian diamonds starting Jan. 1 followed by phased-in restrictions on indirect imports of Russian gems from around March 1.

The implementation of the decision will depend heavily on India, home to 90% of the world's cutting and polishing of the rare gems.

"We are not happy with the announced timeline for implementation of restrictions," Vipul Shah, chairman of the Gem Jewellery Export Promotion Council (GJEPC) said in a statement.

"Recognising the diversity of our industry, we believe there should be more flexibility in these timelines," he said.

The GJEPC said that it would collaborate closely with the World Diamond Council (WDC) and other stakeholders to minimize potential disruptions for small and marginal diamond units, which employ millions of people.

The Indian industry has already been facing tough times, with exports of cut and polished diamonds plummeting by 29% from a year ago to $9.96 billion during April to October, according to data compiled by GJEPC.

Indian diamond units stopped buying Russian diamonds long ago and are unlikely to face any challenges in complying with the G7 rules, said Colin Shah, managing director of Kama Jewellery.

Russia's share in India's rough diamond imports has decreased to a negligible level from around 30% a few years ago, he said. (Reporting by Rajendra Jadhav; Editing by Toby Chopra)