UPDATE 1-Belgian public sector plans strikes this week
* Public sector workers plan strike on Thurs
* Rail strike to begin at 10 p.m. (2000 GMT) on Wed
* International services, such as Eurostar, set to be hit
* Strike is protest over pension reform (Updates to add strike for entire public sector)
BRUSSELS, Dec 19 (Reuters) - Belgian workers in public transport, schools, hospitals and government buildings will stage 24-hour strikes later this week in protest over pension reform, part of the new government's austerity plan to reduce the budget deficit.
The country's rail system will stop operating from 10 p.m. (2000 GMT) on Wednesday and other public services from the post to the metro will shut down on Thursday.
"They want us to work longer and get a lower pension," said Chris Reniers, secretary-general of ACOD, adding that the government aimed to push through laws affecting the public sector on Thursday.
"We are asking for a dialogue and for some of the items to be changed," she said. "This strike is an initial warning."
Jos Digneffe, head of rail union ACOD Spoor, said the rail action would affect passenger and goods trains, including high-speed international services, such as the Eurostar to London, the Thalys to Paris and the ICE trains into Germany.
Digneffe said the unions wanted clarity as to whether rail personnel would be affected by the changes.
Belgium's new government is trying to raise the effective retirement age, currently averaging about 59 years, by raising the age at which workers can claim an early pension. The official retirement age is 65 years.
The pension reform is part of the 2012 budget plan to reduce Belgium's public sector deficit to below the EU limit of 3 percent of gross domestic product next year and reassure investors that Belgium has its finances under control.
Ratings agencies Standard & Poor's and Moody's have both cut their ratings for Belgium in the past month, citing concerns about its high debt, slowing economic growth and cost of rescuing its financial sector, notably banking group Dexia .
The yield on Belgium's 10-year government debt was around 4.4 percent on Tuesday, and the spread over equivalent German bunds, a sign of the perceived risk of holding Belgian debt, was about 2.5 percentage points, double what it was at the end of June.
The strike will be the second show of union opposition to the two-week-old government's cuts after some 50,000 Belgians took to the streets at the start of December. (Reporting by Philip Blenkinsop; Editing by Mark Heinrich and David Brunnstrom)