OSLO, April 16 (Reuters) - Almost 25,000 private-sector workers in Norway will go on strike with immediate effect after negotiations with employers broke down, and the conflict is set to escalate next week, two major labour unions said on Sunday. Another 16,000 workers are due to strike from April 21 unless an agreement is found, and the conflict could ultimately grow to around 200,000 workers, unions have said, but is not expected to affect Norway's production of oil and natural gas. The Norwegian Confederation of Trade Unions (LO) was negotiating on behalf of 185,000 members, while the smaller Confederation of Vocational Unions (YS) represented a further 16,000 in the talks. The Confederation of Norwegian Enterprise (NHO), representing employers, argued wages should not be allowed to rise to an extent that would risk inflation spinning out of control. Norwegian headline inflation is expected to ease to 4.9% in 2023 from 5.8% last year, according to a key report from a commission with members from labour unions, employers' federations and Statistics Norway.

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