TOKYO, Sept 11 (Reuters) - Japanese government bonds gained on Friday, lifted by a surge in U.S. Treasuries, a slip by Tokyo stocks in the wake of the yen's appreciation and as revised gross domestic data showed Japan's economy may have crawled out of recession but still stood on shaky ground.
* Tokyo's Nikkei average lost 0.5 percent to support JGBs, hurt as the yen struck a seven-month high against the dollar.
* Shorter-dated JGBs continued to gain, with two- and five-year yields at or near four-year lows, on persistent demand from domestic banks looking for a safe haven to park their funds made ample by the Bank of Japan's easy monetary policy and slow lending growth.
* The two-year yield was unchanged at 0.210 percent, its lowest since September 2005. The five-year yield fell 1 basis point to 0.585 percent. A drop below 0.580 percent would take it to a four-year low.
* The yield curve until the 20-years flattened a touch on Friday. The five-year/20-year yield spread tightened by 1 basis point to 146.5 basis points after steepening from a three-week low of 143 basis points struck the previous week.
* A steepening bias seen on the JGB yield curve this week eased slightly after U.S. Treasuries rallied on a robust 30-year auction on Thursday.
* "The surge by Treasuries came at a time when the recent steepening of the JGB curve appeared poised to be reversed. We could see the curve flatten in the next week or two," said Akito Fukunaga, a fixed-income strategist at Credit Suisse.
* Revised data showed Japan's GDP grew 0.6 percent in April-June from the previous quarter, against a median market forecast for a 0.9 percent expansion. It translated into annualised growth of 2.3 percent, down from an initial reading of 3.7 percent. The economy pulled out of a full year of sharp contraction during the quarter.
* December 10-year JGB futures gained 0.24 point to 139.17. The benchmark 10-year yield fell 1.5 basis points to 1.305 percent. (Reporting by Shinichi Saoshiro; Editing by Michael Watson)