TULSA, Okla. (AP) -- Gas pipeline operator Williams Partners LP said Tuesday that it will sell 8.5 million stock units and use the proceeds to pay down debt.
The partnership, a unit of Williams Cos. Inc., borrowed money under its credit line to pay for capital spending and other costs. Any proceeds left from the offering after paying down debt will be used for general purposes, the company said.
The Tulsa, Okla., company also will give underwriters a 30-day option to buy up to 1.275 million additional units.
Joint book-running managers are Barclays, Citigroup, BofA Merrill Lynch, Morgan Stanley, UBS, Jefferies, Credit Suisse and Wells Fargo. The co-managing underwriters are J.P. Morgan; Goldman Sachs, Deutsche Bank, RBC Capital Markets and Raymond James.
The shares fell $1.87, or 3.5 percent, to $51.20 during after-hours trading. They had climbed 47 cents to close the regular session at $53.07.

