Honeywell International (HON) shares jumped Tuesday to an all-time high after Elliott Investment Management said it has built a $5 billion-plus position in the industrials conglomerate and is seeking a breakup of the company.

Elliott said in a statement that it had sent a letter to Honeywell's board of directors seeking separations of the aerospace and automation businesses as standalone companies.

The hedge fund said it believed such a split out of the two companies would result in share-price increases of between 51% and 75% over the next two years as they benefit from more focused management and a simplified structure.

"The conglomerate structure that once suited Honeywell no longer does, and the time has come to embrace simplification," Elliott said, noting that "uneven execution, inconsistent financial results and an underperforming share price have diminished the Company's strong record of value creation over the last five years."

Honeywell One of Few US Conglomerates Yet to Break Up

Honeywell is one of the few industrial conglomerates that has yet to break up, although it announced plans last month to streamline its business and spin off its advanced materials division.

Other storied industrial conglomerates have seen their stock soar after breaking up.

General Electric’s three-way breakup was completed in April this year, for instance, and shares of its standalone companies have jumped, with power generation business GE Vernova's (GEV) stock more than doubling this year.

Bloomberg, which earlier reported Elliott's position in Honeywell, said the hedge fund's stake is one of its largest-ever single investment in a firm. It also said Elliott is now among the top five shareholders in Honeywell.

Charlotte, N.C.-based Honeywell last month posted lower-than-estimated quarterly sales and lowered its revenue guidance as demand for its industrial automation products slumped. 

Honeywell shares are up 4.6% Tuesday morning and are up more than 12% this year.