Bulgaria may need more time to respond to concessions proposed by Russian gas giant Gazprom in an EU antitrust case, its energy minister says, adding that while Sofia see the concessions as positive it will like to see them expanded, Business Day writes, quoted by Focus News Agency.

A provisional agreement announced in March would see Gazprom avoid a fine of up to 10% of its global turnover over EU charges it abused its dominant market position and overcharged clients in eight Eastern European nations.

The deal is subject to feedback from EU states and market players that should be sent by May 4 and could be amended or even abandoned.

Bulgaria, which almost completely relies on Russian natural gas supplies, needed more clarity on the concessions and were to send questions to Brussels later on Monday, interim energy minister Nikolay Pavlov said.

"We see the proposals as positive but we want them to be expanded," Pavlov said after meeting politicians from the election-winning GERB party, expected to form a coalition government in early May.

"There are quite a few ambiguities on the proposed commitments. If we do not get answers on time, we will ask for the deadline to be extended, because the information is not sufficient," he said.

Gazprom’s offer would see it scrap contract terms that bar clients from exporting its gas to other countries and tie deals to investments in pipelines. The company would also link its prices to benchmarks such as European gas market hub prices, rather than oil, and allow clients to renegotiate prices every two years.