The Canadian arms of Grant Thornton International and BDO International announced plan to merge their businesses.

Independent accounting firm Briggs & Veselka Co. has acquired a Houston neighbor, local CPA firm Pirsch & Mills LLP.

Business technology solutions provider Net@Work has acquired Apptech Inc., a Cheshire, Conn.-based consulting firm specializing in Sage Pro ERP sales and support.

Integrated business technology solutions provider Net@Work has acquired Westchester, N.Y.-based Spitz Consulting Systems, an ACT! by Sage Software reseller and consultant.Previously, Net@Work did not offer ACT!, which offers small companies contact management services such as needs analysis, data discovery, database design, software installation, data importing, training and follow-up support, through its customer relationship management practice.

Two Pittsburgh financial advisors have merged their independent accounting, tax and investment advisory practices to form ATI Financial Services.The firm’s initials stand for accounting, taxes and investments, and are meant to reflect the core businesses of the new company, which will also provide comprehensive financial planning, insurance and other financial services.

Leon & Partners LLP announced that it will become part of neighboring Houston firm MiriFox & Rodriguez PC.

Business-information provider D&B Corp. has acquired First Research for $22.5 million in cash.

A new partnership in New Milford, Conn., has been doing business as Dumas Estate and Tax Management since the start of 2007.

Carlin, Charron & Rosen, a regional CPA and business advisory firm in New England, has ended its merger negotiations with accounting firm consolidator UHY Advisors.

Midwestern regional firm Clifton Gunderson has acquired Chavarria Dunne & Lamey LLC of Albuquerque, N.M.

Financial and accounting services staffer AccountAbilities Inc. has agreed to acquire California-based ReStaff Services, a staffing company that operates under the name Staffing.com and generates annual revenues of roughly $20 million.

Blue & Co. LLC will acquire a 20-person accounting firm based in Columbus, Ohio.Blue’s deal to acquire Sheridan Barton Vasko & Co., which will operate under the Blue & Co. name, is expected to be completed June 1. Financial terms of the merger were not disclosed.

Two northern New York accounting firms recently announced their merger, in a deal effective Jan. 1.

The Thomson Corp. announced that it has acquired CrossBorder Solutions, a tax software company whose products are used for the planning and compliance needs of corporations.

Sage Software Select resellers Blytheco Business Solutions and Macdonald Consulting Group have merged to form Blytheco LLC.

Long Island accounting firm Janover Rubinroit LLC has merged with tax and estate specialists Roberts, Rick & Moses LLP, in addition to relocating and expanding its New York offices.Financial terms of the deal were not disclosed.

In a merger of companies that primarily provide accounting technology to schools, Dallas-based Tyler Technologies Inc. announced that it has acquired Bangor, Maine’s Advanced Data Systems Inc.Publicly-traded Tyler said that it had acquired all of ADS’s common stock, as well as an office building used in the business, for approximately $4.2 million in cash. ADS develops and sells fund accounting solutions, primarily in New England.

Tax prep giant H&R Block Inc. reported a third-quarter loss last week, pointing to its struggling mortgage lending arm even at the start of a strong beginning to the fourth quarter’s tax season -- where the company makes the bulk of its profits.Block said that it lost $44.7 million in the three months ending Jan. 31, compared to gains of $12.1 million in the same period a year ago. Revenue for the same quarter increased to $955.1 million, from $860.3 million.

Accountabilities Inc., a provider of staffing and marketing services to CPA firms, announced that it has entered into an asset purchase and reorganization agreement with Tilden Associates Inc. and TFP Acquisition Co. LLC.Tilden’s chief line of business is the sale of automotive franchises, and the administration and support of auto repair centers. TFB Acquisition is a newly formed company controlled by Tilden’s chairman and president, Robert Baskind.

LogicalApps, a provider of embedded governance software, announced that it has acquired the Integra product line from Applimation, a provider of management consulting and software for businesses using Oracle and PeopleSoft applications.