Adds share price reaction in paragraph 4

By Christoph Steitz and Tom Käckenhoff

FRANKFURT/DUESSELDORF, Feb 18 (Reuters) - Thyssenkrupp could spin off, list or divest its materials trading division as soon as this year and is considering changing the business's legal form to keep control in case of a majority sale, three people familiar with the matter said.

The deliberations around Thyssenkrupp Materials Services $(MX)$, which accounts for more than a third of Thyssenkrupp's sales, mark another step in the group's overhaul under CEO Miguel Lopez after a spin-off of its defence division and while talks to sell its steel unit continue.

MX, which made 11.4 billion euros ($13.5 billion) in sales last year, could be separated out via a listing already in autumn, one of the people said.

Shares in the company, which makes everything from car parts to chemical plants, rose as much as 4.2% following the report and were up 3.6% at 1257 GMT.

THYSSENKRUPP MULLS CHANGE OF LEGAL FORM

Thyssenkrupp TKAG.DE said in a statement to Reuters that MX was "well on track" to become capital-market-ready. The company has previously said it was seeking a stand-alone solution for the business.

The timing of MX's potential divestment and the possible change in legal form have not been previously reported.

One condition for a successful divestment is that the division - which apart from trading metals and other raw materials also offers warehousing services - is showing an improved performance in the second fiscal quarter ending March, the people said.

Thyssenkrupp is also examining whether to give MX the legal form of a so-called KGaA, a structure that ensures control stays with the parent even if most of it were to be sold, they added.

The discussions are ongoing and no firm decisions have been made, the sources said, adding details could still change.

"We are confident that Materials Services can be successfully brought to the capital market – even in a challenging environment. As with any planned transaction, the exact timing will depend on market conditions," Thyssenkrupp said in the statement.

MX, which sees the U.S. as its key market, faces consolidation among its rivals there, with Ryerson RYN.N having recently merged with Olympic Steel ZEUS.O and Worthington Steel WS.N planning to buy Kloeckner & Co KCOGn.DE for $2.4 billion.

MX is currently the number-four steel service player there after Reliance RS.N, Ryerson/Olympic Steel and Kloeckner.

"We see potential for consolidation in the market, but we do not view this potential as a risk, but rather as an opportunity for Materials Services," Thyssenkrupp said in its statement.

Based on Worthington's proposed bid for Kloeckner, which values the German firm at 8.5 times its core profit, Thyssenkrupp Materials Services could fetch about 2 billion euros in a deal.

($1 = 0.8442 euros)

(Reporting by Christoph Steitz and Tom KaeckenhoffEditing by Tomasz Janowski)

((christoph.steitz@thomsonreuters.com; +49 30 220 133 647;))