* Developed Markets Fund down 2.9 pct in January
* Takes 1.3 pct hit from slide in BT's share price
* Comcast, Amazon, Facebook all help to offset losses
By Maiya Keidan
LONDON, Feb 17 (Reuters) - After ending last year downheavily, the value of London-based Lansdowne Partners' main fundslid again in January after shares in crisis-hit BT Groupplunged, a letter to investors seen by Reuters showed.
Lansdowne, one of Britain's oldest hedge funds, struggledlast year, losing 15 percent in its main vehicle, the $9.3billion Developed Markets Fund, according to a report by HSBC.The same fund fell a further 2.9 percent in January, the lettershowed.
The biggest drag in the opening weeks of the year was BT,which lost the fund 1.3 percent when it shed a fifth of itsvalue on Jan. 24 after it made deeper provisions for anaccounting scandal in Italy and warned on profit.
The continued poor performance comes after a tough periodfor many hedge funds, which prompted Lansdowne Chairman StuartRoden to tell the industry it needed to stop making excuses forpoor performance.
Among other holdings to weigh on January's performance wasBritish satellite telecoms company Inmarsat, which costthe fund 0.9 percent.
Helping offset some of those losses, the firm made gainsfrom a number of 'long' positions, a bet the share price willrise, in firms including Comcast Corp, Amazon.com and Facebook Inc, the letter showed.
Other winnng investments included International ConsolidatedAirlines and Booker Group Plc.
A spokesman for Lansdowne declined to comment. (Reporting by Maiya Keidan; Editing by Keith Weir)