May 28 (Reuters) - A tender to develop Iran's Azadegan oil field will be held before next Friday, National Iranian Oil Company Managing Director Ali Kardor told state-run Press TV on Sunday.

Invitation letters to submit proposals will be sent to 29 international companies, including Shell RDSa.L , Total TOTF.PA , CNPC, Lukoil LKOH.MM , Pertamina PERTM.UL and OMV OMVV.VI , Press TV reported.

The Azadegan field is located in southwest Iran near the border with Iraq. It has 37 billion barrels of oil, Petroleum Engineering and Development Company Managing Director Seyed Noureddin Shahnazizadeh told Mehr News agency this month.

(Reporting By Babak Dehghanpisheh in Baghdad; Editing by Susan Thomas) ((babak.dehghanpisheh@thomsonreuters.com;))