While Wanda did not give a reason for the sale, local business magazine Caixin quoted Wang saying the deal would greatly reduce Wanda Commercial's debt level and help the property unit to achieve an "asset-light" operation.
"Through this asset transfer, Wanda Commercial's debt ratio will be greatly reduced, all the proceeds will be used to repay loans. Wanda Commercial plans to repay most of the bank loans this year," Wang told Caixin.
S&P downgraded Wanda Commercial in December citing rising financial leverage and slower-than-expected asset disposal at China's largest commercial developer.
Another downgrade would push the rating into "junk" category.
Wanda has been investing heavily in entertainment, leisure and financial businesses and the buying spree has drawn the attention of Chinese regulators, who ordered lenders last month to assess exposure to overseas deals by Wanda, HNA Group, Anbang Insurance and Fosun.
Wanda had earmarked a more than 300 billion yuan investment for its cultural and tourism projects. It has also been very active globally, buying U.S. cinema chain operator AMC Entertainment Holdings Inc and taking a controlling stake in U.S. film studio Legendary Entertainment last year.
The 91 percent stake in Wanda cultural and tourism projects, located across the country from the northern city of Harbin to Kunming in the south, will fetch 29.58 billion yuan. The price tag for the hotels is 33.6 billion yuan.
Sunac and Wanda are expected to sign an agreement by the end of this month.
Shares in Wanda Hotel Development surged more than 150 percent after the news.
Wanda said Tianjin-based Sunac, led by magnate Sun Hongbin, will be responsible for all the loans for the projects, but the brand name and design of the projects will remain unchanged, and they will still be operated and managed by Wanda.
Sunac, whose shares in Hong Kong were suspended from trading ahead of what it said would be a "very substantial acquisition" announcement, declined to comment further.