German regulators have approved Deutsche Post's plan to raise the price of stamps for standard letters next year, a move analysts said could add up to 100 million euros ($129 million) to the company's mail revenues.

The price hike, the first in 15 years, was due to general cost trends, the German network agency said on Monday.

Davy Research analysts have said Deutsche Post's regulated mail revenues total around 3.5 billion euros.

"Therefore the increased stamp price could add up to an incremental 100 million euros to Deutsche Post mail revenues," Davy said in a note on September 17, a few days after the company announced proposed price hikes.

Mail prices for letters weighing up to 20 grams will rise to 58 cents from January 1, 2013 from the current price of 55 cents, the first price increase since 1997.

Letters of up to 1 kilogram will be priced at 2.40 euros from 2.20 euros.

Analysts said the price increases represent an average 2.8 percent hike for all affected products of the company.

The mail division's revenue rose to 6.85 billion euros in the first half of this year, slightly above the 6.78 billion for the same period last year.

(Reporting by Marilyn Gerlach; Editing by Mark Potter)