Bangkok, Thailand.

Japan's largest law firm, Nishimura & Asahi, will merge with a Thai firm, becoming just the second major Japanese firm to do so.

Nishimura & Asahi's eight-lawyer Bangkok office will merge with 60-lawyer SCL Law Group in October; the merged Bangkok office will operate under the new name SCL Nishimura.

SCL was founded in 2005 by managing partner Chavalit Uttasart, who focuses on intellectual property and mergers and acquisitions. Previously, Uttasart was a partner at Thai firm International Legal Counsellors Thailand Ltd.

The SCL group comprises eight entities: Siam City Law Offices Ltd., the main entity that advises on corporate law and dispute resolution; IP arm Chavalit & Associates Ltd.; tax arm SCL Tax Consultants Ltd.; foreign investment arm SCL International Ltd.; and Chavalit & Partners Ltd., which is based in the coastal resort of Hua Hin in southern Thailand, advises on property, corporate and tax matters. The firm also has three overseas offices: Siam City Law (Myanmar) Co. Ltd. in Yangon; SCL Law Offices Ltd. (SCL Lao) in Vientiane, Laos; and SCL SP&P Co. Ltd. (Cambodia) in Phnom Penh. SCL's offices outside Thailand are not part of the Nishimura merger.

Until July last year, SCL was the Thai member firm of Singaporean firm RHTLaw Taylor Wessing's Southeast Asia-focused legal network, ASEAN Plus Group.

The Thai merger comes six years after Nishimura & Asahi opened its Bangkok office, which is led by Japan-qualified M&A partner Hideshi Obara. Thai-qualified M&A specialist Jirapong Sriwat is the only other partner in the Bangkok office.

"The [Southeast Asia] region is one of the biggest trading partners globally for Japan, as well as one of Japan's most favored destinations for [foreign direct investment]," said Nishimura & Asahi's Tokyo-based managing partner, Masaki Hosaka, in a statement, adding that the merger will bring growth and returns on investment for clients and the firm in the region.

Japan is the top foreign direct investor in Thailand, investing more than $1.2 billion last year—29% of total FDI into Southeast Asia's second-largest economy—mostly in metal products and machinery, according to the Thailand Board of Investment. There are more than 1,700 Japanese businesses in Thailand, of which about 40% are in manufacturing, according to the Japanese Chamber of Commerce in Bangkok.

Elsewhere in Southeast Asia, Nishimura & Asahi has offices in Vietnam, Myanmar and Singapore, as well as an alliance in Indonesia with Walalangi & Partners. Last year, the firm opened an office in New York—the second top Japanese firm to do so, after Nagashima Ohno & Tsunematsu in 2010.

Nishimura & Asahi will also be the second of Japan's top firms—known as the Big Four—to merge with a Thai firm. Mori Hamada & Matsumoto was the first, merging its three-lawyer Bangkok office with 45-lawyer Chandler & Thong-ek Law Offices in 2017. Since then, Mori Hamada's Bangkok office, which operates as Chandler MHM, grew to have more than 60 lawyers; in 2018, Chandler MHM recruited a four-lawyer corporate and finance team from Clifford Chance's Bangkok office as the Magic Circle firm was closing the office.

The rest of the Big Four Japanese firms, Nagashima Ohno and Anderson Mori & Tomotsune, also have offices in Bangkok, since 2014 and 2016, respectively.