Initial nominations for US polymer-grade and chemical-grade May propylene contract prices are calling for a rollover at 71 cents/lb and 69.50 cents/lb, respectively, sources said Friday.

ExxonMobil Chemical is the only producer with propylene contract nominations announced at this time, sources added.

This marks the second consecutive nominations for rollover for the year -- April's nomination was also flat, however, those contract prices settled mid-month at a 1-cent decrease.

The nominations for May were within the expectations of market participants, who expected an increase of up to half-cent.

Spot PGP was last assessed April 18 at 67.75-68.25 cents/lb delivered USG basis, while spot CGP was assessed at 64.75-65.25 cents/lb delivered USG basis.

Spot refinery-grade propylene was assessed Thursday at 60-60.50 cents/lb delivered USG basis. April was heard bid at 59.75 cents/lb Mont Belvieu pipeline basis, offered at 61 cents/lb Mont Belvieu pipeline basis, and traded three for three consecutive days at 60.25 cents/lb Mont Belvieu pipeline basis.

April and May PGP offers were heard at 70 cents/lb Mont Belvieu pipeline basis and traded twice on Thursday at 68.50 cents/lb Mont Belvieu pipeline basis for April delivery.

US propylene contracts are settled on a monthly basis between major producers and buyers. The process includes price nominations by producers and subsequent negotiations with customers.