Led by strong performances from Twinspires.com and Youbet.com, collective handle for the four largest domestic advance deposit wagering platforms increased by roughly 15% in the first quarter of the year, while their overall share of the national betting pie grew by more than 2%.

Twinspires, Youbet, TVG, and XpressBet.com combined for about $370.9 million in handle in the first quarter, yielding a 15% increase over the $322.6 million of the same period last year, according to data compiled by The Blood-Horse from company filings and an Oregon Racing Commission report.

The combined total of the “Big Four” also represents nearly a 12% share of all U.S. handle, based on a first-quarter figure of $3.1 billion reported by Equibase, up from roughly a 9.5% share a year ago. The share numbers are skewed somewhat in this comparison, because the ADWs also offer wagering on certain international race meets, including those in Canada, while Equibase’s totals are for U.S. racing only.

The growth took place during a quarter when overall handle on U.S. racing declined 9.4%, showing again the shift of many bettors to ADWs, which offer wagering through Internet, telephone, and mobile-device platforms.

Youbet and Twinspires, which is owned by Churchill Downs Inc., showed the largest individual gains during the quarter, jumping 29.9% and 24.5%, respectively, based on company-reported handle totals of $124 million and $76.7 million. Twinspires’ total recorded with the Oregon Racing Commission, which regulates hubs where the Big Four and other ADWs process wagers, was nearly $3 million higher at $79.6 million. Attempts to clarify the differential with respective officials weren’t immediately successful.

TVG, which was acquired in January by privately-held Betfair, processed $110.6 million in wagers, up 2.3% over the $108.2 million of 2008, according ORC data. XpressBet, which is owned by Magna Entertainment Corp., lost a percentage point to $56.7 million, down from $57.3 million last year.

The total first-quarter handle processed through Oregon was $281,595,151, a 20% drop from last year. But that total was impacted by the loss of nearly $118 million wagers Youbet chose to funnel outside the state. In the first quarter of 2008, Youbet ran all of its wagers through Oregon, which receives a quarter-cent on each dollar processed through the state hub.

Other Oregon ADW hub totals for the first quarter include: U.S. Off-Track/Paydog, $7,005,243; Racing Channel, $16,083,124; BetPad, $605,000; AmWest Entertainment, $4,846,525; and Racing 2 Day, $54,475.