Recent studies are showing that DSL out hit high-speed cable modem services in the first quarter of the year…again.

Leichtman Research Group (LRG), in a report that includes figures from the 20 largest cable and DSL providers in the U.S., said top DSL providers added a record 1.66 million subs in Q1, representing 54 percent of the net broadband additions for the period.

It marked the sixth consecutive quarter in which DSL providers added more broadband subs than cable, acquiring 1.1 million more customers in that extended timeframe, LRG noted.

Cable was no slouch, either, as the top providers in the category also achieved a quarterly record, signing up 1.4 million subs, LRG said.

Overall, the top 20 broadband service providers had 46 million high-speed subs. Cable maintained its lead in the U.S. with 25.8 million broadband subs (56 percent share), compared to DSL’s 20.2 million.

Based on DSL growth forecasts, some analysts, including those at Information Gatekeepers, are predicting that U.S. DSL subs will exceed high-speed cable customers in late 2006.

Cable, however, is leading the way when it comes to access speed. According to LRG stats, 85 percent of cable broadband lines offered speeds of over 2.5 Mbps (downstream), versus just 14 percent of DSL lines.

“With the second quarter being a consistently slower quarter for broadband adds, it is unlikely that the record-setting trend will continue, but clearly there are millions of dial-up subscribers ready to switch to broadband in the near future,” said LRG President & Principal Analyst Bruce Leichtman, in a statement.

At the end of Q1, the top five broadband service providers were: Comcast (8.95 million), AT&T (7.4 million), Verizon (5.68 million, a figure that includes the company’s fiber-to-the-premises customers), Time Warner Cable (5.16 million), and BellSouth (3.14 million).