MUMBAI, Aug 25 (Reuters) - India has imposed a 20% duty on exports of parboiled rice with immediate effect, a move that could further reduce shipments from the world's largest exporter and lift global rice prices that already trade near their highest in 12-years.

Last month, India surprised buyers by imposing a ban on the export of widely consumed non-basmati white rice, following a ban on broken rice exports last year.

India's move to ban non basmati white rice prompted some buyers to increase purchases of parboiled rice and lifted its prices to a record high level, said a Mumbai-based dealer with a global trade house.

"With this duty, Indian parboiled rice would become as expensive as supplies from Thailand and Pakistan. There is hardly any option for buyers now," the dealer said.

India exported 7.4 million tons of parboiled rice in 2022.

In July, the United Nations food agency's rice price index jumped to its highest level in nearly 12 years as prices in key exporting countries jumped on strong demand after India imposed restrictions on the exports. (Reporting by Rajendra Jadhav Editing by Chris Reese and Tomasz Janowski)