Deutsche Post has not yet filed for regulatory approval for the increase, the paper reported on Sunday, citing no sources.

"That is total speculation," a spokesman for Deutsche Post said on Sunday.

Once the federal regulator has decided how much postage can be raised by, the company then decides which prices to adjust and submit filings to the regulator for them.

Chief Executive Frank Appel said in May that Deutsche Post could raise its prices for both letters and parcels.

Deutsche Post last raised the postage for a standard letter in early 2016, to 0.70 euros from 0.62 euros.

Earlier this month, it announced plans to raise the price of shipping packages of books and other goods in response to rising transport costs and volumes.

(Reporting by Maria Sheahan; Additional reporting by Matthias Inverardi; Editing by Alexander Smith)