UPDATE 1-Chinese agencies back Tengzhong-Hummer deal-Mofcom

* Both Mofcom and NDRC supportive of Tengzhong bid - Mofcom

* Tengzhong has submitted documents to NDRC - source (Adds comments from source in paragraphs 5 to 7)

BEIJING, July 15 (Reuters) - China's Ministry of Commerce on Wednesday played down reports that it is at odds with the economic planning agency over a controversial deal for a little-known Chinese company to buy GM's GMGMQ.PK Hummer unit.

Spokesman Yao Jian said: "The commerce ministry and the National Development and Reform Commission both hold a supportive attitude towards Chinese companies venturing abroad."

A politically connected source told Reuters that the NDRC seemed to oppose the deal, due partly to environmental concerns about the fuel-hungry Hummer car and the vague plans that suitor Sichuan Tengzhong Heavy Industrial Machinery has for the brand. [ID:nHKG239049]

"This is not a decision for the government. It's an active strategy for companies in the course of globalisation. That's a long-term trend," Yao told a news conference.

Tengzhong has begun the long official approval process by submitting documents related to the acquisition to the NDRC, said a source close to the matter.

"This kicks off the approval process," said the source, who asked not to be identified because of sensitive nature of the matter.

Several government agencies are involved in different aspects of the approval process, which means the commerce ministry would not require documents from Tengzhong until closer to the end of the process, said the source.

Yao said his ministry, which must approve any deal valued above $100 million, had not received an application.

GM hopes to finalise the sale by the end of the third quarter. (Reporting by Langi Chiang and Kirby Chien; Editing by Lincoln Feast)