Adds quote from fund manager in paragraph 16, background

By Pritam Biswas and Saeed Azhar

Dec 8 (Reuters) - Berkshire Hathaway BRKa.N shook up its management on Monday, weeks before Warren Buffett hands control to Greg Abel, with its key investment manager, Todd Combs, departing for JPMorgan Chase JPM.N to support the bank's $1.5 trillion project to finance and invest in strategically-placed U.S. companies.

The changes at Berkshire showed Abel making his mark on the company before taking the reins in the New Year. Abel's transition to CEO on Jan. 1 closes Buffett's extraordinary six decades heading Berkshire Hathaway, where he became a household name, a multi-billionaire and an American success story. Warren Buffett, the 95-year-old investor, is known for his market instincts and long-held nickname "the Oracle of Omaha."

"Abel is positioning trusted lieutenants and fresh talent to balance continuity with modernization at Berkshire; instilling changes under the eye of Buffet as Chairman allows him to make his mark while showing shareholders that the Oracle of Omaha approves," said Michael Ashley Schulman, the Chief Investment Officer at Running Point Capital.

The shake up will see Berkshire's longtime finance chief Marc Hamburg, who joined in 1987, retire on June 1, 2027 after four decades at the conglomerate. Charles Chang, CFO of Berkshire Hathaway Energy, will succeed Hamburg next year.

Investment manager Combs will leave to head the strategic investment group of JPMorgan's new security and resiliency initiative, according to the bank. The Wall Street giant earlier this year launched the initiative, a $1.5 trillion, decade-long plan to support industries deemed vital to U.S. economic security and resilience.

Combs and another Berkshire investment manager Ted Weschler were once expected to take over the company's equity portfolio, having helped Buffett invest in stocks, but the CEO had in recent years said Abel could handle it.

The appointments underscore Berkshire's tradition of choosing leaders who uphold its culture, show strong business judgment and support its distinctive operating model, the company said, adding it remains well positioned for the future.

Berkshire also announced changes in its insurance and non-insurance operations and named Michael O'Sullivan as the general counsel, marking the creation of a new position at the company.

However, the lot of non-insurance businesses - including industrial products, building products, BNSF, Berkshire Hathaway Energy, Pilot and McLane - will remain under Abel's direct oversight once he takes over as CEO.

ADVISORY COUNCIL

JPMorgan also set up an external advisory council of public- and private-sector leaders to help steer its "Security and Resiliency Initiative" that aims to commit up to $10 billion in direct equity and venture capital investments to help selected U.S. companies.

The council will be chaired by JPMorgan CEO Jamie Dimon, and include members such as Amazon AMZN.O founder Jeff Bezos, Dell Technologies DELL.N CEO Michael Dell, and former U.S. Secretary of State Condoleezza Rice. Combs will also be a part of this advisory council.

"It should be no surprise that Jamie Dimon is able to create a Team America - a group of innovative individuals who will pragmatically steer capital stewardship well into the future for the bank," said David Wagner, head of equities and Portfolio Manager at Aptus Capital Advisors LLC.

The hire from Berkshire, Combs, will partner with the firm's Commercial & Investment Bank and Asset & Wealth Management units to pursue opportunities spanning middle-market and large corporate clients in defense, aerospace, healthcare and energy, the bank said.

"JPMorgan has assembled a top tier government, defense, tech, and industrial brain trust for its SRI advisory council that should well understand the interplay of Washington, D.C. politics, government contractors, and corporate America," Schulman said.

Combs, who previously served on the JPMorgan board, will join the bank in January and report to Dimon. Dimon described Combs in the bank's press release on Monday as "one of the greatest investors and leaders I’ve known, having successfully managed investments alongside the most respected and successful long-term investor of our time, Warren Buffett."

(Reporting by Pritam Biswas in Bengaluru and Jonathan Stempel and Megan Davies in New York; additional reporting by Saeed Azhar; Editing by Megan Davies, Anil D'Silva, Leroy Leo and Nick Zieminski)

((Pritam.Biswas@thomsonreuters.com;))