UPDATE 1-Constellation to sell London unit to Goldman

NEW YORK, Jan 20 (Reuters) - Constellation Energy Group Inc (CEG.N) said on Tuesday it had reached a definitive agreement to sell the majority of its London-based commodities business to Goldman Sachs (GS.N).

The sale was a part of the Baltimore-based utility and power company's previously announced plan to boost its liquidity and cut its collateral requirements.

Financial details of the transaction were not released.

Constellation, which agreed last month to sell nearly half its nuclear power business to Electricite de France SA (EDF.PA) for $4.5 billion, is also seeking to sell its Houston-based natural gas trading operation.

The London-based business includes Constellation's coal and freight platforms, as well as its European-focused power, gas and carbon trading operations. The deal is expected to close by the end of the first quarter.

Constellation, owner of utility Baltimore Gas & Electric as well as a whole power business, had faced a cash crunch last year when it disclosed its could face billions of dollars in collateral requirements related to its trading positions.

In December, the company said it would cut up to 8 percent of its work force, or about 800 positions, mostly from its commodities trading group. (Reporting by Matt Daily, editing by Maureen Bavdek)