FRANKFURT, June 13 (Reuters) - Gazprom's Nord Stream 1 gas pipeline will undergo its annual maintenance for ten days next month, its operator said on Monday, suggesting no gas will flow to Germany during that period.

Currently, it is planned that maintenance work will be done from 0600 CET (0400 GMT) on July 11 to 0600 CET on July 21, the company said.

Last year, there were no flows to Germany during July 15-22. (Reporting by Christoph Steitz; Editing by Jan Harvey)