UPDATE 1-Tesco comes under union fire on foreign labour

* UNI union criticises Tesco practices in Asia, U.S.

* UK union to raise its concerns at Tesco AGM on Friday

* UK union Usdaw says does not recognise UNI's criticisms

(Adds Usdaw comment)

LONDON, June 30 (Reuters) - A trade union group has attacked Tesco (TSCO.L), Britain's biggest retailer, over its treatment of workers in some foreign markets, days ahead of an anticipated showdown at its annual meeting with a domestic union.

The UNI Tesco Global Union Alliance on Tuesday issued reports criticising Tesco's labour practices in Thailand, South Korea and the United States, following local complaints.

The reports allege that Tesco coerced employees in Thailand and South Korea into working unpaid overtime, and refused to discuss the possibility of organised labour representation in the United States.

Tesco, which employs around 470,000 staff in 14 countries, said the reports were "a travesty".

"This is a politically motivated report paid for by a union which is trying to recruit more members," a Tesco spokesman said in a statement. "The allegations are untrue."

Usdaw, which represents many of Tesco's staff in Britain, said it had a good working relationship with the firm.

"The allegations made in this report are not something Usdaw would recognise in relation to Tesco," it said in a statement.

UNI said it had "good relations and regular dialogue" with French retail giant Carrefour (CARR.PA) and German supermarkets group Metro (MEOG.DE) but that Tesco had refused to meet or talk with UNI officials.

"Tesco's employment practices fall short of its published global labour principles in many countries. What we want to see is local consistency with Tesco's global standards, which is not happening at the moment," Alke Bossiger, the head of department for UNI's commerce unit told reporters at a press conference.

The UNI's reports concern Tesco's 120 Fresh & Easy convenience stores in the United States, 476 Tesco Lotus shops in Thailand and 246 outlets in South Korea.

Tesco is due to hold its annual general meeting in Glasgow on Friday where it will face a resolution from Unite, Britain's largest trade union, calling on management to implement its policies on workers' rights more effectively.

The campaign is backed by investor corporate governance adviser Pirc.

Last year's AGM was dominated by celebrity television chef Hugh Fearnley-Whittingstall's campaign to get Tesco to improve the welfare standards for chickens, but only 9 percent of shareholders backed his resolution

Tesco reported a full-year pretax profit of 3.13 billion pounds ($5.2 billion) in April, 10 percent up on 2007-08. [ID:nLL127432] ($1=.6076 pounds) (Reporting by Rhys Jones; Editing by Greg Mahlich)