The Sonoma County Vintners group on Monday released the lineup for the its third annual barrel trade auction and again both Kosta Browne and Williams Selyem — the two wineries that have battled it out for top honors in previous years — have special lots entered.

This year’s event, which will be held April 21 at the Vintners Inn in Santa Rosa, will include 115 participating wineries, with 43 of those vintners new to the competition. All 17 American Viticultural Areas in the county are represented.

The event last year raised nearly $700,000 from trade buyers, who in turn typically resell the wine to their best customers. The proceeds go to the Sonoma County Vintners, the county’s main trade group that represents 200 wineries and wine-affiliated businesses.

The past two years have featured a battle for the highest bid between the hottest cult pinot noir producers in the Russian River Valley, Kosta Browne and Williams Selyem.

Last year, Kosta Browne received a $46,000 bid for its 10-case lot of pinot noir wine from a Texas grocery chain, averaging $383 per bottle. Williams Selyem was next, with a $41,000 bid for a 20-case lot of pinot noir, which translated to $170 per bottle.

Kosta Browne this year will double its lot production to 20 cases with a blend from the Freestone Vineyard in Sonoma Coast. The wine has been fermented in a range of vessels, from stainless steel tank to wood and concrete open tops, as well as a concrete egg and amphorae.

Williams Selyem’s entry will be “Sonata No. 3” — a pinot noir lot with grapes from three of its estate properties: the Williams Selyem Estate, Lewis MacGregor Estate and Drake Estate.

Other notable submissions include a collaboration among winemakers Matt Courtney of Arista Winery in Healdsburg, Mike Sullivan of Benovia Winery in Santa Rosa and Bob Cabral of Three Sticks Wines in Sonoma, to produce a 10-case “A Celebration of Saralee” lot that pays tribute to the late vineyard owner Saralee McClelland Kunde.

In addition, Healdsburg’s Dry Creek Vineyard and Rochioli Vineyards & Winery have combined to produce a sauvignon musqué blend using fruit drawn equally from both estates.

You can reach Staff Writer Bill Swindell at 521-5223 or bill.swindell@pressdemocrat.com. On Twitter @BillSwindell.