* Property bubble index up just 0.02 points at 1.24 in Q2
* SNB, government, lenders have worked to shrink bubble
* Switzerland becoming test case, says UBS
ZURICH, Aug 5 (Reuters) - Steps to shrink Switzerland's housing bubble are taking effect, according to a quarterly study by Swiss bank UBS.
Mortgage lenders, the government and the central bank have come up with a variety of measures to combat rising property prices fuelled by ultra-low interest rates, immigration and Switzerland's appeal as a safe haven for financial investors.
Those include temporarily demanding more capital against mortgage lending, plans to no longer allow pension funds as down payments for property, and stiffer standards for mortgage loans.
"The tougher capital requirements thus far imposed on mortgage borrowers can be regarded as a success story," UBS said in its Swiss Real Estate Bubble Index on Tuesday.
The index - which compares a series of data sets including purchase prices, rents and household debt - rose just 0.02 points to 1.24 points in the second quarter. It stood at 1.15 in the second quarter of 2013.
Risks remained in hotspots like lakeside residential areas in Zurich and Geneva, UBS said.
The Swiss National Bank (SNB), which cannot lift interest rates due to a cap it has set on the Swiss franc, has long fretted about rising house prices and bank lending.
In January, the government doubled the level of capital banks must hold against their mortgage book on the advice of the SNB, after a failed attempt last year to cool the housing boom.
Switzerland is increasingly becoming a test case for how to control mortgage lending, said UBS.
"The regulator's credible backdrop of threats suggests that in case of renewed acceleration of prices and debt, the regulatory screw would be tightened further," UBS said.
Housing bubbles are also a worry in Britain and in Germany, where Finance Minister Wolfgang Schaeuble said recently that low interest rates were already spawning "dangerous" rises in domestic property prices. (Reporting By Katharina Bart. Additional reporting by Alice Baghdjian. Editing by John Stonestreet)