Natural Resource Partners LP (NYSE: NRP) will offer 8.5 million common units representing limited partner interests, the company said Oct. 6.

Underwriters will be given a monthlong option to purchase about 1.3 million additional common units, the company said.

Net proceeds will fund part of the purchase price for the acquisition of nonoperated working interests in Williston Basin oil and natural gas assets from an affiliate of Kaiser-Francis Oil Co., Natural Resource Partners said.

Citigroup Inc. (NYSE: C), Wells Fargo Securities LLC, BofA Merrill Lynch and UBS Investment Bank are joint book-running managers. Stifel and BB&T Capital Markets are co-managers, the company said.

Houston-based Natural Resource Partners LP is an MLP that owns interests in domestic oil, natural gas, coal and industrial minerals.