UPDATE 1-Aegon Q1 results beat forecasts

* Q1 net profit 521 mln euros vs 276 mln seen in poll

* Impairments fall to four-year low

* Underlying profit 425 mlns euros vs 415 mln in poll

AMSTERDAM, May 10 (Reuters) - Dutch life insurer Aegon soundly beat profit expectations on Thursday thanks to the combination of cost reductions, improved equity markets, lower impairments, and positive revaluations.

Aegon's first-quarter net profit was 521 million euros ($673.7 million), up 59 percent compared with the same period last year, and well above the average forecast of 276 million euro in a Reuters poll based on eight analysts.

Aegon, a top 10 insurer in the U.S. where it owns life insurer Transamerica, has been cutting costs and jobs, particularly in the Netherlands and Britain.

"We were pleased with the low level of impairments during the quarter, their lowest in four years. At the same time, it continues to be our priority to maintain Aegon's strong capital position in this period of continued economic uncertainty," Chief Executive Alex Wynaendts said in a statement.

Impairments fell 34 percent to 41 million euros.

Aegon received 3 billion euros in financial aid in the 2008 credit crisis, and repaid the state in full in June 2011 - the first bailed-out Dutch firm to do so. It will resume paying dividends, as announced last year.

Aegon, which also offers pension products and asset management services, reported a 3 percent rise in underlying operating profit before tax to 425 million euros, above analysts' average forecast for 415 million euros.

The underlying profit figure excludes special items, such as fair value items, gains or losses on investments and impairments.