* FTSE 100 closes up 1.7 percent at 5,602.54
* U.S. gains fuel rally; Carnival leads blue-chip risers
* Oils buoyed by BP well news
By Simon Jessop
LONDON, Sept 20 (Reuters) - Britain's leading share index extended early gains to close strongly on Monday, after U.S. market bulls helped London to its highest close since late April.
The FTSE 100 closed up 94.09 points, or 1.7 percent, at 5,602.54, more than reversing the 0.6 percent decline in Friday's session after risk appetite made a strong return.
"Traditional defensives have enjoyed their day in the sun, with investors taking the view that Friday's sell-off was overdone," said Yusuf Heusen, senior sales trader at IG Index, referring to demand for dividend-yielding stocks.
"It has been a well supported rally from a mix of sectors, with cruise operator Carnival the strongest blue chip ahead of tomorrow's update," he added.
Carnival ended the day the top FTSE 100 gainer, up 5 percent.
Gains for oil major BP fuelled the rally earlier in the session after the firm announced it had permanently killed the Gulf of Mexico oil well that began spilling oil and ravaging its share price in April.
BP ended the day up just over 2 percent, with fellow integrated oil and gas majors Royal Dutch Shell and BG Group also up over 2 percent.
Looking ahead, technical factors remain positive in the short term, said Nicolas Suiffet at Paris-based technical analysts Trading Central.
"Both 20-day and 50-day moving averages are bullish with Bollinger bands widening substantially. Daily MACD is holding above its signal line and short-term momentum oscillators remain positive with further upward potential," he said.
Next resistance should be met around 5,665 and 5,755 points "in the forthcoming days", although a break below 5,510 could see it decline towards next support at 5,350, said Suiffet.
Gains at the U.S. open helped underpin the FTSE, traders said, with all eyes on the next Federal Reserve interest rate decision on Tuesday and UK home sales data later in the week for the next macro push.
BANKS GAIN The heavyweight banking sector helped drive the rally, adding 12 points to the index, buoyed by the return of risk appetite and a positive broker note from JP Morgan Cazenove.
Barclays ended up 2.8 percent, just pipping sector peer Lloyds Banking Group, up 2.7 percent.
Miners also rose, lifted by gold's move to a fresh high, with precious metals miner Fresnillo ending up 0.7 percent.
Leading the FTSE fallers was insurance buyout vehicle Resolution, which ended down 1.6 percent after a strong run prior to its entry to the FTSE 100 at the index's latest reshuffle. (Editing by David Cowell)