* June factory activity strongest since Nov 2013-HSBC PMI

* Overall new orders at 15-month high, export orders dip

* Adds to signs of stabilization in economy on policy support

BEIJING, July 1 (Reuters) - Activity in China's factory sector expanded in June for the first time in six months as new orders jumped, a private survey showed on Tuesday, reinforcing signs of stabilisation in the economy as the government steps up policy support.

The final reading of the HSBC/Markit purchasing managers' index (PMI) for June rose to 50.7 from May's 49.4, surging past the 50-point level that separates growth in activity from contraction for the first time since December.

The PMI was slightly weaker than the flash reading of 50.8, but was the highest since November, when it was also 50.8.

The sub-index for new orders, a gauge of demand at home and abroad, hit a 15-month high of 51.8 in June, although the sub-index for new export orders fell, signalling firmer domestic demand.

(Reporting by Kevin Yao; Editing by Kim Coghill)