Verdi union calls for strike at Frankfurt airport on Jan. 15

FRANKFURT (Reuters) - German union Verdi on Friday said it was calling on security staff at Frankfurt airport <FRAG.DE> to go on strike on Tuesday to put pressure on management in wage talks.

Verdi said it was negotiating on behalf of 23,000 security workers in Germany.

Wage talks are to resume on Jan. 23, it said.

On Thursday, more than 640 flights in Germany were cancelled due to security staff strikes at Duesseldorf, Cologne and Stuttgart airports.

(Reporting by Arno Schuetze, editing by Tassilo Hummel)