Starboard Value is preparing to nominate directors to Knife River Corp’s seven-member board, escalating pressure on the construction-materials supplier to improve profitability or consider a sale. The activist investor is seeking a plan to lift Knife River’s margins to 22% by fiscal year 2029, compared with about 15% in the quarter ended June 30 and roughly 30% at some rivals. Knife River has a market value of $2.8 billion, while its stock has declined 24% over the past 12 months. The fund has lined up some candidates and is considering others. Knife River says it remains focused on margin expansion and profitable growth and has confidence in its leadership and strategy, but its response did not provide further detail on achieving the targeted improvement. Starboard’s next steps come as Jeffrey Smith prepares to discuss selected investments at the annual 13D Monitor Active-Passive Investor Summit in New York on Tuesday.