* JD.com says in preliminary stages of evaluating a bid

* Elliott's 62 pence per share proposal rejected

* Shares jump as much as 38% to 64.9 pence

LONDON, Feb 19 (Reuters) - Currys shares soared on Monday after Chinese online retailer JD.com joined U.S. activist investor Elliott Advisors in a battle to buy the British electricals group, which has already rejected Elliott's opening bid of $880 million.

Currys stock jumped as much as 38% after JD.com confirmed it was interested in the retailer that sells fridges, washing machines, computers and other electrical goods across Britain, Ireland, Sweden, Norway, Denmark and Finland.

Currys on Saturday rejected Elliott's possible cash offer of 62 pence per share, a 700 million pounds ($883 million) proposal it said significantly undervalued the company.

Elliott said it was considering another proposal.

Analysts speculated that Currys' low valuation had triggered the interest.

The group has struggled to grow over the last two years as sales fell back after spiking in the pandemic and high inflation squeezed consumer incomes.

Before the interest was made public, Currys shares had lost 54% of their value in the last two years.

That helped attract JD.com, one of China's leading e-commerce giants and the country's top electronics retailer, even though Currys still makes two-thirds of its sales from stores.

Currys has around a quarter of Britain's 20 billion pound electricals market, making 5.1 billion pounds of sales in the UK and Ireland and 4.4 billion pounds from other markets last year. It announced the sale of its Greek unit in November.

The interest lifted shares in its European rivals. Germany's Ceconomy rose 5% and France's Fnac Darty climbed 3.6% on Monday.

JD.com said it was "in the very preliminary stages of evaluating a possible transaction that may include a cash offer for the entire issued share capital of Currys."

JD.com representatives had held exploratory talks with Currys in recent weeks, Britain's Telegraph newspaper said on Sunday.

Currys declined to comment on JD.Com's statement, while Elliott Advisors, which already owns Britain's Waterstones bookshops, did not comment further on Monday.

Currys, which formerly traded under the Dixons and Carphone Warehouse brands in Britain, said in January it expected to benefit as consumer confidence improved and as it turned around its Nordics business.

But despite that optimism, its shares were trading at a forward price-to-earnings ratio of 5.58, amongst the lowest in the STOXX 600 retail sector.

"This move is fresh evidence that UK assets are considered to offer significant value, still partly weighed down by the impact of Brexit, the weaker pound, and the stagnating UK economy," said Susannah Streeter, head of money and markets at Hargreaves Lansdown.

Under UK takeover rules, Elliott has until 1700 GMT on March 16 to make a firm offer for Currys or walk away.

Mike Ashley's Frasers Group owns an 11% stake in Currys, partly through financial instruments.

($1 = 0.7924 pounds) (Reporting by Sarah Young in London, Maria Ponnezhath in Bengaluru Additional reporting by Sophie Yu in Beijing and Helen Reid and Samuel Indyk in London Editing by Kirsten Donovan and Mark Potter)