FOREX-Yen struggles; data cheers sterling

* Dollar extends gains, hits fresh 4-mth high vs yen

* BOJ seen easing at next Tuesday's policy meeting

* Rebound in UK growth helps push sterling higher

* U.S. Q3 GDP next event risk

SYDNEY, Oct 26 (Reuters) - The yen languished at four-month lows versus the dollar on Friday, on track for a second week of losses as markets geared up for the Bank of Japan to ease policy next week, while a rebound in UK growth helped shore up sterling.

Commodity currencies also came under pressure after lacklustre results from Apple hit risk sentiment, but they have since regained their composure.

The dollar rose to 80.38 yen, bringing into view the June peak of 80.63. A break there would take it back to highs not seen since April. It is up more than 1 percent so far this week, adding to last week's 1.1 percent gain.

The euro was at 103.95 yen, not far off Tuesday's five-month peak of 104.59. It is up 0.7 percent on the week, following a 1.7 percent rally in the previous week.

``The move may have further to run leading into Tuesday's BOJ announcement. But we believe that lower U.S. yields eventually, and a BOJ falling short on action, will see USD/JPY back lower,'' Kiran Kowshik, a strategist at BNP Paribas wrote in a client note.

``Hence, we opt to use any near term upward pressure to enter a conditional short recommendation (from 80.60) targeting 78.00 with a stop placed above 81.90 (above April 20 high).''

Japanese inflation data due around 2330 GMT could reinforce expectations for the BOJ to ease next week. The bank is under pressure to stimulate the economy until its 1-percent-inflation target is achieved.

Having drifted lower for much of this week, the euro looked set to finish in the red, hampered by uncertainty about when Spain will request for a bailout and trigger the European Central Bank's bond-buying programme.

The single currency was at $1.2943, well off the Oct. 17 high of $1.3140. Still, it is seen hemmed in a $1.2800/1.3200 range until Spain asks for aid, traders said.

The stand out performer on Thursday was sterling, which powered up to $1.6118 from two-week lows of $1.5914 after Britain posted its strongest growth in five years in the third quarter, thanks in part to the Olympics.

The data prompted markets to reassess the chances of more stimulus from the central bank, which helped drive the pound higher.

The next key focus is the advanced reading of U.S. third-quarter gross domestic product due later in the day. The annualised rate of growth in the world's largest economy is seen at 1.9 percent, picking up from an anaemic 1.3 percent pace.

Both the Australian and New Zealand currencies are on track to end the week higher, in part due to local events such as a higher-than-expected reading of Australian inflation earlier in the week.

A less dovish Reserve Bank of New Zealand has also helped lift the kiwi.

In his first speech as RBNZ governor, Graeme Wheeler on Friday reaffirmed the bank's commitment to maintaining price stability. He also said intervention is unlikely to have a sustained impact on bringing down the high dollar.

The Aussie last traded at $1.0353, having survived yet another downside test to $1.0230 this week. It is up 0.2 percent on the week. The kiwi stood at $0.8194, not far off a three-week high of $0.8243. On the week, it is up 0.4 percent.