Gazprom (GAZP.RS) Deputy Chairman Alexander Medvedev Tuesday defended the state-controlled natural gas giant's long-term, oil-linked contracts, saying there's no point talking about linking European prices to the spot market.

Gazprom is under investigation by the European Union for alleged violations of antitrust rules. It has adjusted contracts for some clients in its most lucrative market,
Europe , but has insisted on keeping natural gas prices linked to the oil price.

Speaking at the Gas Russia Forum in
Moscow , Mr. Medvedev said the EU probe appeared to be aimed at changing the way contracts are structured to link them to prices on the spot market for natural gas.

But he said such a move would be "dangerous" as the long-term contracts in their current form provided stability and reliability for consumers and the supplier.

Mr. Medvedev said
Europe would need an extra 100 billion cubic meters of gas by 2020. He said potential shale gas developments couldn't cover those needs as such projects have an unclear future and the gas would be expensive.