* NAB to cut mortgage rates from May 16
* Westpac to cut mortgage rates from May 23
* CBA to cut mortgage rates May 20
* ANZ to cut mortgage rates May 13
* Central bank cuts official rate by 25 basis points (Recasts top of story, adds CBA, ANZ cuts)
SYDNEY, May 3 (Reuters) - Australia's four biggest banks said on Tuesday that they would all cut variable home loan rates by 25 basis points following the central bank's move to lower the cash rate by a quarter point to an all-time low of 1.75 percent.
National Australia Bank, the nation's No.1 lender, was joined by No.2 lender Commonwealth Bank of Australia . No.3 lender Westpac Banking Corp and No.4 Australia and New Zealand Banking Group in passing on the full rate cut to their customers.
NAB's cut, effective May 16, will pull its variable home loan rate down to 5.35 percent, it said. The lender will also reduce its variable business lending rates by 25 basis points.
Westpac Banking Corp followed suit, saying it would cut variable home loan and residential investment property loan rates by 25 basis points effective May 23.
CBA's cut will take effect from May 20 and ANZ from May 13, they said, respectively.
The Reserve Bank of Australia lowered interest rates on Tuesday, its first easing in a year, as it seeks to restrain a rising currency and insulate the economy from creeping deflation.
Banking shares rose on the prospect of increased demand for mortgages, lifting the benchmark index 1.8 percent. ($1 = 1.3221 Australian dollars) (Reporting by Swati Pandey; Editing by Stephen Coates and Ryan Woo)