The two under construction NGL pipelines, Sand Hills Pipeline and Southern Hills Pipeline, are currently being developed by DCP Midstream which is a 50-50 joint venture company between Spectra Energy and Phillips 66.

Upon closing of the deal, the three companies will each own one-third interest in the two pipelines and will equally contribute funds for the completion of Sand Hills and Southern Hills pipelines.

Spectra Energy did not disclose the value of the agreement but is expected to invest $700m to $800m in the two pipeline projects.

Spectra Energy president and chief executive officer Greg Ebel said the pipeline projects will complement the company’s current pipeline network in North America.

"As these NGL pipelines begin serving customers later this year and in 2013, they will directly add attractive, stable earnings and cash flow to Spectra Energy’s results," Ebel added.

The Sand Hills is a 720 miles and 20in pipeline which will transports NGL from Permian Basin and Eagle Ford Shale to key markets on Gulf coast. The initial capacity of 200,000 barrels per day (bpd) can be increased to 350,000 bpd later.

It is expected to be operational in the second quarter of 2013.

The Southern Hills is a 900miles long pipeline which is being constructed to transport NGL from the Mid-Continent to Mont Belvieu in Texas.

It has an initial capacity of 150,000 bpd which can be expanded to 175,000 bpd. The pipeline is scheduled to begin services in mid-2013.