Proxy advisory firm Glass Lewis said Timken Co shareholders should vote for a non-binding proposal to break up the company's ball-bearings and steel businesses.
The break up was proposed by activist hedge fund Relational Investors and the California State Teachers' Retirement System (CalSTRS).
Glass Lewis was the second major proxy advisory firm to back the proposal. Institutional Shareholder Services made a similar recommendation earlier in the week.
Timken management opposes a split, saying the integrated company enjoys a variety of advantages that would be destroyed if the company were broken in two. The United Steel Workers union has sided with management on the issue.
Glass Lewis said in its report that "shareholders would strongly benefit from a more thorough review of this potential strategic alternative. The incumbent board has displayed, in our view, a clear and troubling track record of responsiveness to shareholder concern and, perhaps of greater note here, has strongly expressed its intention to pursue the status quo."
Relational Investors and CalSTRS believe a split would create two companies with a combined market capitalization larger than the current one.
"We thought our case was compelling from the beginning - it's been reflected in the stock price," David Batchelder, co-founder and principal of Relational, said in an interview on Wednesday.
Timken shares are up more than 25 percent since Relational announced its stake and called for a breakup in November. That compares with a roughly 13 percent increase in the Standard & Poor's 500 index over the same period.
Batchelder said that if shareholders support the proposal and Timken decides to disregard the vote, Relational would consider putting up a slate of board nominees at next year's annual meeting.
(Reporting By Michael Erman; editing by Andrew Hay)