* EU would have to halve plastic bag use by 2017
* Next parliament, member states still have to finalise the law
STRASBOURG, France, April 16 (Reuters) - The European Parliament passed a directive on Wednesday aimed at cutting the use of thin single-use plastic carrier bags by 50 percent by 2017 and 80 percent two years later.
The directive leaves it to individual states to choose their strategy, for example taxing bags or banning them. EU ministers are due to debate the law in June and the parliament will take it up again later this year following elections in May.
Some 100 billion plastic bags are used every year within the European Union and an estimated 8 billion end up as litter that turns up in Europe's seas.
The stomachs of 94 percent of all birds in the North Sea contain plastic, according to figures from the European Commission.
Environmental groups welcomed Wednesday's vote, but representatives of the European plastics industry were critical.
"Discarded plastic bags are killing millions of marine animals each year. It has become a massive problem across Europe and one we must deal with together," Chris Davies, Liberal Democrat European Environment spokesperson, said.
Karl-H. Foerster, executive director of the trade association PlasticsEurope, said Europe needed better waste management rather than new rules.
"A ban on plastics bags is not the solution to tackle the problem of irresponsible disposal," he said, adding that letting countries set their own rules would be "detrimental to the free movement of goods in Europe".
Plastic bag use varies significantly across member states.
In Denmark, where they are taxed, the average person uses 4 single-use bags per year - the lowest in the European Union. Meanwhile 466 plastic bags are used per person in Portugal, Poland and Slovakia, according to Commission figures. (Editing by Tom Heneghan)