Shanghai's monthly house price index fell in June, ending a 15-month rally amid increasing supply and shrinking sales.

The index, which tracks price movements of existing homes citywide, lost 17 points to 2,565 last month, the first drop since March 2009. It rose 0.15 percent in May, 0.69 percent in April and 0.81 percent in March.

"Home prices failed to remain at record high as more owners put their houses for sale while buying momentum continued to be slack," said Tao Ting, an analyst at the index compiler, Shanghai Existing House Index Office. "About 80 percent of areas monitored by the office saw price cuts in the past month."

He noted that the "central government seems to remain firm in its stance to curtail investment in multiple properties for speculative purposes and therefore, no major rebound in prices could be anticipated in the near future."

The prices of existing homes in five downtown districts were mixed in June. Prices dropped in Huangpu, Changning and Xuhui while Luwan and Jing'an grew slightly.

Home prices the city's outlying areas fell an average 1.42 percent last month, against an average drop of 1.02 percent in May, the compiler said.