NEW DELHI, April 21 (Reuters) - South Korea's LG and Samsung have sued India's government to quash a policy which increases payouts to electronic-waste recyclers, court filings show, joining other major companies in contesting the country's environmental rules citing business impact. LG's filing in the Delhi High Court, which is not public but was reviewed by Reuters on Monday, said the pricing rules "fail to take into consideration that merely by fleecing companies and taxing them in the name of the 'polluter pays principle', the (government) objectives sought to be achieved cannot be achieved." Samsung wrote to Modi's office last year, the company's court filing showed, saying the new pricing was "5-15 times the price currently paid."