* Initial offers flat to up 2.9% v.s. this quarter

* Local spot premiums hovering at around $140-$150/T - sources

* Asia still in glut despite shift in some supply to Europe

* Negotiations expected to continue until late this month

TOKYO, June 1 (Reuters) - Global aluminium producers have offered Japanese buyers premiums of $172 to $177 a tonne for July-September primary metal shipments, which would be between unchanged and 2.9% higher compared with the current quarter, four sources directly involved in quarterly pricing talks said on Wednesday.

Japan is Asia's biggest importer of the metal. The premiums for primary metal shipments it agrees to pay each quarter over the London Metal Exchange (LME) cash price set the benchmark for the region.

For the April-June quarter, Japanese buyers agreed to pay a premium of $172 per tonne , down 2.8% from the prior quarter.

The latest quarterly pricing negotiations began late last month between Japanese buyers and global suppliers, including Rio Tinto Ltd and South32 Ltd, and are expected to continue until late this month.

Japanese buyers said the initial offers were too high, as local spot premiums were hovering at around $140-$150 a tonne, reflecting slack demand from automakers amid a global supply chain crunch.

"A significant volume of aluminium has been transported in recent months from LME warehouses in Asia to Europe, where premiums were much higher," a source at a Japanese trading house said. "But the Asian market is still in a glut due to the lack of easy container arrangements to ship more metal out of the region."

Behind the glut was also increased exportation of the metal from China to elsewhere in Asia, some in the form of semi-manufactured products, another source at a producer said. Shanghai aluminium prices, having been lower than LME prices, have encouraged Chinese producers to export metal, that source said.

There is concern that supply may be disrupted by the deepening conflict between Russia and Ukraine and possible sanctions on Russian aluminium giant Rusal. But supply to Japan has been steady, and premium negotiations will be done on an assumption that the current conditions will continue, the sources said. (Reporting by Yuka Obayashi; Editing by Christopher Cushing and Bradley Perrett)