Pakistan Prime Minister Yousuf Raza Gilani on Wednesday allowed traders to export onion to India for orders contracted before January 4, the day a ban was imposed on supply of the commodity via the Wagah land border.The Prime Minister's directive, which was forwarded to the Commerce Ministry, will apply only to orders that were finalised by Pakistan traders before the ban was imposed and for which payments had already been made by Indian importers.PTI quoting sources in the Pakistani government reports that the ban on the export of onion to India via the land route will remain in place.Authorities said they had imposed the ban to stabilise prices in the domestic market, which they claimed had surged after the onion exports began in mid-December.However, Pakistani traders have opposed the ban, saying sales to other countries were continuing without any hindrance.Traders from Punjab, Pakistan's most populous province, pointed out that onion was being freely exported from Karachi in Sindh province to Sri Lanka, Malaysia, Indonesia, Dubai and Mumbai in India, and said the stopping of exports via Wagah amounted to discrimination.Indian merchants had blocked the supply of tomato to Pakistan for a day to protest the ban. Pakistani traders said this pushed the price of tomato up to 100 rupees a kilogram in the domestic market.