Comcast ( CMCSA) posted a $297 million loss in its first quarter, but said cable and high-speed Internet subscriber additions were stronger than expected and revenue rose almost 10% when adjusted for the acquisition of AT&T Broadband. Unadjusted, revenue was $5.52 billion, up from $2.67 billion last year. The company lost $297 million, or 13 cents a share, in the latest quarter compared with a loss of $89 million, or 9 cents a share, last year. Pro forma for the AT&T acquisition, first-quarter revenue rose 9.7% from $5.03 billion last year, while earnings before interest, taxes, depreciation and amortization rose 22.1% to $1.64 billion, excluding some one-time expenses in the year-ago period. Comcast said it added about 57,000 cable subscribers in the first quarter and now expects full-year cable additions to be 75,000 to 100,000. It added 417,000 high-speed Internet subscribers in the quarter, and now expects to add 1.6 million during 2003 for a total of 5.2 million.