UPDATE 2-UK clears LSE plan to buy LCH Clearnet

LONDON, Dec 14 (Reuters) - Britain's competition watchdog

has given the green light to the London Stock Exchange's

planned purchase of clearing house LCH.Clearnet.

The Office of Fair Trading on Friday gave its unconditional

approval, clearing what was viewed as the biggest regulatory

hurdle to the proposed 600 million euro ($785 million) tie-up.

The timing of the deal is still unclear, however, as both

parties renegotiate terms to reflect higher capital requirements

being imposed on exchanges by European regulators overhauling

the financial system after the banking crisis.

Clearing houses sit between trading firms and ensure trades

of securities such as stocks and bonds are completed, holding

cash to refund firms left out of pocket by a counterparty

default.

They have taken on greater importance since the collapse of

Lehman Brothers four years ago and regulators want to force more

trading through such vehicles to ensure smoothly functioning

markets even at times of stress.

The LSE said on Friday it was still in discussions over

"potential changes to the commercial terms of the transaction"

on account of new recommendations from European regulators.

Under the deal terms agreed in April, the LSE proposes to

buy up to 60 percent of the clearing house for 19 euros per

share.

"I think both parties want the deal to go through so

something will be arranged... My guess is that the LSE will get

something but probably not the full amount of the additional

cost that they'll have to bear," said James Hamilton, an analyst

at Numis Securities.

The European Securities and Markets Authority may not

finalise its demands until early next year, and only then will

the LSE know by how much it must renegotiate the terms of its

LCH takeover.

Analysts expected LCH's capital shortfall will be less than

early estimates and should come in at about 220 million euros.

The LSE would only need to pay 60 percent of that, but that

would still leave it on the hook for at least 100 million euros,

which its shareholders will want factored into the terms of the

LCH takeover.

LCH.Clearnet shareholders include nearly one hundred of the

world's largest trading banks and two exchanges - the London

Metal Exchange and NYSE Euronext.