Dec 5 (Reuters) - Endeavour Mining's top boss said on Thursday the Canadian firm was reaching out to Centamin shareholders to back its $1.9 billion merger plan, days after the British gold miner's board rejected the all-stock proposal.

The UK-based company said earlier this week the proposal did not offer any benefits for its shareholders.

Endeavour Chief Executive Officer Sébastien de Montessus did not comment on the valuation. Some Centamin investors and industry analysts have said Endeavour's proposed bid should be increased.

As per Reuters calculation, Endeavour's proposal values Centamin at 126.27 pence a share, while the stock has a median target price of 132.50 pence according to Eikon data from Refinitiv.

"Analysts price targets for both companies are much higher than their current share prices...if we were just relying on price targets, I don't think any of us would be talking in this industry," de Montessus said.

Gold miners have bulked up with a record $30.5 billion in deals this year to replace dwindling reserves and appeal to investors who in recent years have shunned the sector because of disappointing returns.

Combining with Centamin would make Endeavour more attractive to funds and shareholders who have called for consolidation in the sector, de Montessus said on a call.

In a statement on Wednesday, Centamin Chairman Josef El-Raghy urged shareholders to take no action on the proposal.

"It is the board's belief that the proposal made by Endeavour sits in stark contrast with Centamin's strategy," El-Raghy said.

Centamin stock, which has lagged Endeavour's over the last two years, had jumped nearly 15% to 128.8 pence on Tuesday when Endeavour disclosed its proposal. Endeavour fell 4% in that session.

Current takeover rules in the UK give West Africa-focussed Endeavour until Dec. 31 to drum up support to succeed in its plans.

The Canadian miner attempted to buy Aca cia Mining a few years ago but talks collapsed. Barrick Gold recently took control of the precious metals miner, which was previously listed on the London Stock Exchange.

(Reporting by Jeff Lewis in Toronto and Muvija M in Bengaluru; Editing by Sweta Singh)