UPDATE 1-German bonds' ECB optimism fades as Treasury yields shoot higher

* Euro zone periphery govt bond yields (Adds details, updates prices)

AMSTERDAM, March 12 (Reuters) - Benchmark German government bonds gave up most of the gains they made a day earlier, when the European Central Bank said it would accelerate the pace of its bond buying, with yields tracking U.S. Treasuries higher on Friday.

Investors were watching the market for any sign of additional ECB support after ECB President Christine Lagarde said the increase in the pace of bond buying under the bank’s Pandemic Emergency Purchase Programme (PEPP) would be implemented as of Thursday.

The purchases will see the ECB buy a monthly amount above 60 billion euros but below 100 billion euros, with a small tolerance band around it, sources told Reuters after the decision on Thursday.

But some of the optimism around the purchases, intended to combat a recent rise in global bond yields spurred by growth and inflation bets in the United States, faded on Friday.

Ten-year U.S. Treasury yields rose back above 1.60%. Their German equivalents, the benchmark for the region, rose as high as -0.298% in early trade.

That was above Thursday’s peak at -0.308%, before the ECB announced its decision to increase the pace of its bond buying during the next quarter.

U.S. and German bond yields closely track one another. But that has become a cause of concern as German and other euro zone yields have risen in tandem with U.S. Treasuries, even though the euro area faces a weaker economic outlook. Germany’s 10-year yield was last up 2 basis points to -0.31% at 1232 GMT.

Italian 10-year yields, which outperformed the market on Thursday as the country is among the top beneficiaries of ECB bond buying, were up 2 basis points to 0.63%.

After falling as much as 10 bps following the decision, that puts them just 5 bps lower than Thursday’s highs before the meeting.

The limited market reaction underscores analysts’ view that the increased buying pace will have a limited impact in holding down the bloc’s bond yields. Without an increase to the PEPP envelope -- the total purchases permitted under the programme -- it will just mean the programme will have to end earlier.

“While the ECB is buying some time, the measures will probably not be enough to fully offset the expected further pressure on the term premium from the US long-end,” said Michael Leister, head of interest rate strategy at Commerzbank, referring to the additional yield on longer-dated debt relative to shorter-dated debt.

Euro zone bonds were largely unaffected by headlines that Germany is at the start of a third wave of the coronavirus or that Italy would tighten coronavirus restrictions in some regions from next week. The risk premium on Italy’s 10-year bonds was little changed.

Policymaker Francois Villeroy de Galhau, also the governor of France’s central bank, stressed on Friday that the bank will be flexible with the programme. (Reporting by Yoruk Bahceli; editing by Simon Cameron-Moore, Larry King)