Vietnam has invited about half a dozen foreign investment banks to advise it on selling its stake in dairy producer Vinamilk, sources said, in one of the strongest signs yet of the government getting serious about offloading its most lucrative assets.

Credit Suisse, HSBC, J.P. Morgan Chase , Nomura Holdings, and advisory firm Rothschild are among the firms that recently received requests from Vietnam's government, several sources with direct knowledge of the matter told Reuters.

The people were not authorized to speak to the media.

The Vietnamese government's investment arm, the State Capital Investment Corporation (SCIC), holds a 44.7 percent stake in Vietnam Diary Products JSC, as Vinamilk is formally known.

It intends to sell roughly 10 percent, worth about $900 million at the current market price, then offload the rest incrementally, the sources said.

Vinamilk did not immediately respond to a request for comment. SCIC declined to comment. JPMorgan, Credit Suisse and HSBC declined comment while Nomura and Rothschild had no immediate comment.