Major Dutch warehousing and logistics firm C. Steinweg has bought metal, stevedoring and warehousing company J Oosterom & Zoon for an undisclosed sum, a source with direct knowledge of the matter said.

The source quoted a letter sent by both of the Netherlands- based companies to customers saying Oosterom shareholders, "had decided it was a good time to join forces with Steinweg", which stores metals, chemicals, plastics and soft commodities.

Steinweg, which has offices worldwide, is the only major warehousing and logistics firm that is registered with the London Metal Exchange (LME) and remains independent. It told Reuters in March it was planning to stay that way.

Big trading companies and banks have been buying warehousing firms in a trend criticized by some metals traders, who fear conflicts of interests despite so-called "Chinese walls" that these companies implement to safeguard against information leaks.

The LME, the world's biggest marketplace for industrial metals such as copper and aluminum, oversees a global network of privately owned warehouses where such metals are stored, partly for potential delivery against its contracts.

JP Morgan bought warehouse firm Henry Bath last February, after Goldman Sachs bought U.S.-based Metro. Traders Trafigura, Noble Group and Glencore have all taken charge of their own warehousing units.

Oosterom operates warehouses in Rotterdam that are approved by both the LME and the Minor Metals Trade Association.

The takeover is effective from Jan. 1, and the letter was signed by Oosterom Director Pascal de la Fonteijne and Steinweg Chief Executive Ulf Boll, the source said. (Reuters)