ANCHORAGE (AP) — Two Anchorage-based utility companies have teamed up to purchase a portion of a Cook Inlet gas field under a $152 million deal with ConocoPhillips.

Anchorage Municipal Light and Power and Chugach Electric Association are looking to buy ConocoPhillips’ stake in the Beluga River Unit about 35 miles west of Anchorage. The deal announced Monday calls for ML&P to pay $106 million, increasing its ownership in the field to nearly 60 percent. Chugach Electric is offering $46 million for 10 percent ownership.

Officials with both electric utilities say the purchase will reduce the cost of natural gas and lower rates for customers.

The deal must be approved by the Regulatory Commission of Alaska.

Monday’s announcement comes after ConocoPhillips, hit by low oil prices, revealed plans in July to offer up its portion of the gas field. A spokeswoman for the Houston-based energy company said selling the field would allow ConocoPhillips to focus on “higher growth” areas.

“While historically significant to our company’s investment in Alaska, these are mature assets that no longer fit in our portfolio,” said Amy Burnett, a spokeswoman for ConocoPhillips. “We are pleased to be handing this legacy asset off to the local utilities,” she said in an emailed statement.

Anchorage Mayor Ethan Berkowitz approved of the deal, saying it would provide long-term, affordable and reliable natural gas to city customers.

Anchorage officials said municipal ownership in the Beluga River field has saved ratepayers $239 million over two decades.

Mark Johnston, ML&P general manager, said purchasing ConocoPhillips’ stake could save 30,000 residential and commercial customers about $4 million to $6 million a year. The deal is expected to save Chugach Electric’s 68,000 ratepayers about $2 million to $3 million, according to Chief Executive Brad Evans.