Apartment sales in Vietnam could jump 40 percent this year from 2013, backed by an improved economic outlook, higher property investment and banks boosting house loans, according to property advisor firm CBRE, the Lao Dong (Labour) newspaper reports.     Mid-class and budget apartments accounted for most sales in the first half of 2014, while demand for high-class units also increased, thanks to economic outlook optimism and sellers' promotion packages, the report said.     ----     NOTE: Reuters has not verified this story and does not vouch for its accuracy.   (Hanoi Newsroom; Editing by Sunil Nair)  ((hanoi.newsroom@thomsonreuters.com)(+844 3825 9623))  Keywords: VIETNAM PRESS/