The Indian government threw open its $450 billion retail market to global supermarket giants on Thursday, approving its biggest reform in years that may boost sorely needed investment in Asia's third-largest economy.

Foreign players are already allowed to operate wholesale, or cash & carry, stores.

"The focus is on cash & carry and we have no plans to enter the Indian market with Real or MediaMarkt Saturn," a Metro spokesman said on Thursday, referring to its hypermarket and consumer electronics chains.

The opening up of the market is likely to be of more interest to Metro rivals Wal-Mart and Carrefour The German company has already classed its Real business as non-core and has said it would sell it if the right offer came up.

Metro's Cash & Carry unit entered the Indian market in 2003 and currently has eight stores there, after opening two in Punjab and Mumbai this year.

A spokeswoman for the unit said Metro aimed to open at least five new cash & carry stores in the country a year. "We want to keep up expansion pace and further invest in our Cash & Carry business in India," she said.