BERLIN, April 12 (Reuters) - German Finance Minister Christian Lindner is planning tax relief of more than 20 billion euros ($21.33 billion) to help boost the economy, German magazine Spiegel reported on Friday.

Some 13 billion euros will be freed up by reducing the solidarity tax, introduced after reunification to support poorer states in eastern Germany, according to the report.

Lindner also plans to allow immediate write-offs for climate protection investments, which is also set to free up billions of euros, reported Spiegel.

The finance ministry did not immediately respond to a request for comment.

($1 = 0.9377 euros) (Reporting by Maria Martinez, Writing by Miranda Murray, Editing by Friederike Heine)