Tata Consultancy Services Ltd is giving bonus to its staff on 10th anniversary of its initial public offer (IPO) and is facing a law suit by a white American worker. He has accused India's largest software services exporter of overwhelming favoritism toward workers of South Asian descent in the United States.

In a complaint filed in San Francisco federal court, Steven Heldt said 95 per cent of Tata's 14,000-person US workforce came from South Asia, primarily India, and that the company has violated federal civil rights law by intentionally favoring them in hiring and promotions.

Heldt said he experienced "substantial anti-American sentiment" in his 20 months at TCS, including from a human resources manager who allegedly called Americans "selfish and demanding" and said "I don't like dealing with Americans."

Despite claiming to have been in the industry since 1996, Heldt said Tata saddled him with "menial" or no substantive work as it shuffled him between several jobs, ending with the Californian's firing in March 2014.

Heldt is seeking class-action status for Tata workers and job applicants in the United States since April 2011 who are not of South Asian race or from India, Bangladesh and Nepal. He seeks a halt to discrimination, and unspecified damages.

Meanwhile, TCS on Thursday said it will give a one-time bonus to all eligible employees to mark the 10th anniversary of its initial public offer or IPO. India's biggest outsourcer will give one week's salary for every year of service rendered, a move that will cost the company $423 million or Rs 2,628 crore.

Employees who have completed at least one year in service will be eligible to receive the one-time bonus, TCS said. TCS employs 3.19 lakh consultants worldwide.

The country's biggest software exporter also announced an average salary hike of 8 per cent for its employees in India. Overseas employees will get an average hike of around 2-4 per cent.

TCS was listed in 2004. Its shares have done exceedingly well as the company notched industry-leading growth rates. TCS is now India's biggest firm with a market capitalization of Rs 5 lakh crore. It's also the country's most profitable firm.

TCS reported a 29 per cent fall in its net profit in the fourth quarter ended March 31, 2015, on a sequential basis. Its net profit fell to Rs 3,858 crore in the fourth quarter.