BRUSSELS (Reuters) -European Union countries negotiating changes to the EU's gas storage targets could approve them in time to ease them before the upcoming winter, EU diplomats told Reuters.

The gas storage rules were introduced in 2022 after Russia slashed deliveries following its invasion of Ukraine, to ensure EU countries had a buffer of stored fuel during winter.

They set binding targets for storage levels in February, May, July and September, leading up to a target of having storage filled to 90% capacity by November 1.

Changes being considered for 2026 and 2027 would include replacing the binding November 1 deadline with an aim to hit 90% at any time between October 1 and December 1, while making the targets for earlier months voluntary.

The changes could apply to this year's November 1 target if the rules are finalised and published before that date, the EU diplomats said. One said that this was likely to be the case, although it was probably unlikely that the changes would be enacted in time to affect targets for earlier months this year.

EU countries aim to agree their joint position on the rules next week, after which they must negotiate the final law with the European Parliament.

Member states want to be allowed to deviate by up to 5 percentage points from the 90% target in case of "unfavourable" market conditions, according to a document released this week by Poland, which supervises negotiations as holder of the EU's rotating presidency.

The EU diplomats said some countries, including Germany, are seeking a bigger 10 percentage-point deviation from the target.

The European Commission had initially wanted to extend the existing binding targets for two more years, but met resistance from governments including Germany, France and the Netherlands.

Countries are concerned the targets can inflate gas prices by indicating to the market when European buyers must buy large volumes.