FRANKFURT (Reuters) - Thyssenkrupp's TKAG.DE foundation, the company's largest shareholder, pledged to work with unions and management to appoint a successor to its chairman Ulrich Lehner.

Thyssenkrupp has been gradually dismantling its complex submarines-to-elevators business and last month merged its European steel assets with those of rival Tata, further retreating from a core business.

Shareholders are pushing for a radical overhaul, urging the Essen, Germany-based conglomerate to consider selling its elevators business and materials services division, which distributes non-ferrous metals, alloys and stainless steel.

Major restructuring moves have been opposed by workers and Thyssenkrupp’s management. The company employs 158,000 in businesses ranging from food packaging to naval vessels and industrial services.

Below are stakeholders with the power to influence Thyssenkrupp’s fate:

ALFRIED KRUPP VON BOHLEN AND HALBACH FOUNDATION

The foundation is Thyssenkrupp’s biggest shareholder with a 21 percent stake. It has 11 members and is headed by Ursula Gather, rector of the University of Dortmund, who also sits on the Thyssenkrupp’s supervisory board.

The foundation is tasked with preserving the “unity” of Thyssenkrupp and uses proceeds from Thyssenkrupp’s dividend payments to further good causes in science and education.

The foundation was set up after former chief executive Berthold Beitz persuaded the last member of the Krupp family, Arndt von Bohlen, to put the family shareholding into a foundation tasked with promoting the common good.

Critics say that the unity of the conglomerate has long been compromised with the sale of VDM Group, Steel Americas and the merger of European steel assets with Tata.

The foundation on Tuesday reiterated it will work with labor representatives and the company’s management to develop a long-term strategy for the conglomerate.

German newspaper Handelsblatt reported at the weekend that Gather had held talks with the largest shareholder of Kone KNEBV.HE on a potential merger of the two companies' elevator businesses.

The first conversations took place as early as two years ago but the idea was rebuffed by Hiesinger, who wanted to hold on to Thyssenkrupp’s most profitable division, Handelsblatt reported.

CEVIAN

Swedish activist investor Cevian holds an 18 percent stake in Thyssenkrupp.

Lars Foerberg, founding partner of Cevian Capital, on Tuesday said: “All great and enduring companies renew themselves, taking advantage of their strengths while adapting to new challenges and opportunities. As a large and long-term owner of Thyssenkrupp, Cevian Capital looks forward to supporting the company in achieving these objectives for the benefit of all Thyssenkrupp stakeholders.”

He had renewed his call for deeper restructuring efforts a day after Thyssen struck its steel deal with Tata.

“There is now an urgent need and opportunity to address the significant and persistent underperformance of the industrial businesses,” he said on July 1, adding that Thyssenkrupp could be valued at the equivalent of 50 euros ($58.5) per share.

WORKERS

Unions hold half the seats on Thyssenkrupp’s supervisory board and any deal depends on their support, which Thyssenkrupp has so far won through major concessions regarding job guarantees and a pledge not to close factories. Together with representatives from the Krupp foundation, they have the power to block major strategic moves.

Wilhelm Segerath, head of the Thyssenkrupp works council and a senior official in the IG Metall industrial trade union, on Monday said he regretted the departure of Lehner but understood his move.

ELLIOTT

The U.S. activist investor has said it sees “significant scope for operational improvement” at Thyssenkrupp.

Elliott has a stake of below 3 percent according to its latest filing. It declined to comment on Tuesday.

CHAIRMAN ULRICH LEHNER

Thyssenkrupp’s chairman resigned late on Monday, with his departure effective at the end of the month. Lehner signaled that there had been a clash with not just activist shareholders, but also with the Krupp foundation.

“The confidence of the major shareholders and a joint understanding within the Supervisory Board on the strategic direction of Thyssenkrupp were the basis for my work and a pre-requisite for my promise to Berthold Beitz to successfully further develop the company in the interest of customers, employees and shareholders. This is now no longer given,” Lehner said in a statement late on Monday.

“I take this step consciously to enable a fundamental discussion with our shareholders on the future of Thyssenkrupp. My decision may contribute to creating the necessary awareness with all concerned parties that a break-up of the company and the related loss of many jobs is not an option – neither in the interest of the founder, nor in the interest of the country.”

Lehner’s remarks echoed a similar statement from former Chief Executive Heinrich Hiesinger on July 5, when he resigned, saying a “joint understanding of board and supervisory board on the strategic direction of a company is a key pre-requisite for successfully leading a company”.