(Updates with information from Neuberger Berman, details from company's statement)

Jan 17 (Reuters) - Air Products and Chemicals laid out a more specific timeline on Friday for when its CEO will leave the industrial gases company, as investors began casting votes for directors in a bitterly contested boardroom battle.

The company said it will announce a new president by the end of March and that this person will then become CEO within three months of joining, replacing Seifi Ghasemi.

Air Products also laid out critical governance changes by pledging to split the roles of chairman and CEO, and announcing that Ghasemi, who has been at the helm for a decade, will then retire from the board.

The company, valued at $70.7 billion, is racing to convince investors to back its nine directors, including Ghasemi, at Thursday's annual meeting. Activist investor Mantle Ridge is trying to persuade shareholders to elect four newcomers.

Mantle Ridge argues Air Products needs to lay out a succession plan for its octogenarian CEO, allocate its capital differently and scale back on risky projects. It proposed four executives, including its founder Paul Hilal and a former industry executive, Dennis Reilley, as candidates.

Air Products countered by telling shareholders that the election of any Mantle Ridge nominee "could create extraordinary confusion" about the company's direction and leadership.

Hours after the company laid out its more detailed timeline for when Ghasemi will exit, investment firm Neuberger Berman said it will vote for all four Mantle Ridge nominees. The investment firm cited concerns about "strategic missteps and capital allocation" as well as a "lack of a credible succession plan" for its decision.

Neuberger Berman owns roughly 770,000 shares or a 0.35% stake in Air Products, making it a top-50 shareholder, a spokesperson for the company confirmed.

Earlier, proxy advisory firms Institutional Shareholder Services, Glass Lewis and Egan-Jones recommended that investors back at least some of Mantle Ridge's candidates.

(Reporting by Svea Herbst-Bayliss in New York and Tanay Dhumal in Bengaluru; Editing by Vijay Kishore and Rod Nickel)

((svea.herbst@thomsonreuters.com; +617 233 2138; Reuters Messaging: svea.herbst.thomsonreuters.com@reuters.net))