Norwest said it will sell 15 banks and branches.

The Minneapolis-based bank holding company said it has agreed to sell eight of its banks in southern Minnesota and seven branch offices in South Dakota to four different buyers. The combined assets of the 15 offices totaled $326 million at Dec. 31. Norwest’s total assets were $21 billion at year-end. The sales, which require regulatory approval, are expected to be final within nine months. Terms of the transactions were not disclosed, but company officials said the sales would have no material effect on Norwest’s 1986 results.