NEW DELHI (Reuters) - India will begin field trials in August to buy 126 fighter jets, defence officials said on Wednesday, moving forward on the $10.4 billion deal two days after New Delhi agreed a defence pact with the United States. The announcement of the defence agreement came at the end of US Secretary of State Hillary Clintons trip to India, which aimed to deepen ties and advance defence and civilian nuclear cooperation. Boeings F/A-18 Super Hornet, Frances Dassault Rafale, Lockheed Martin Corps F-16, Russias MiG-35, Swedens Saab JAS-39 Gripen and the Eurofighter Typhoon, produced by a consortium of European companies, are all ready for the trials, Indian defence officials said. The trials will begin in August and will take nearly a year to complete tests in all weather conditions, Indian Defence Ministry spokesman Sitanshu Kar said. The trials for one of the biggest defence contracts currently in play got delayed by Indias April/May elections. This week, the two countries agreed on an end-use monitoring (EUM) pact, a development welcomed by Lockheed and Boeing, the two US companies competing for the contract. This signals an era of increased defence cooperation between the United States and India and we look forward to supporting the requirements of the Indian armed services, said Richard Kirkland, president for Lockheed Martin in South Asia. Boeing said the landmark pact would make it easier to share important US defence technology with India. Boeing looks forward to working within the framework of this agreement to support India in modernising its defence forces, the company said in a statement. Lockheed last year sold six C-130J military transport planes to India for about $1.1 billion, while its U.S.-based rival Boeing has already sealed a $2.1b deal to sell eight maritime patrol aircraft. Both companies along with the Eurofighter Typhoon are the frontrunners, three senior air force officials said privately. Talks between Indian officials and the bidders have been held to work out the trials, and test pilots have been chosen, air force officials said. The trials to test the planes manoeuvrability and effectiveness will be done in phases in various weather conditions, defence officials said. Two US defence industry giants, each vying for a huge fighter-jet contract with India, Wednesday hailed a bilateral accord promising to open the door to greater military commerce between the countries. Lockheed Martin and Boeing are neck-and-neck in the race for the worlds richest fighter aircraft deal in 15 years, worth almost 12 billion dollars, to sell 126 jets to the Indian Air Force. Vivek Lal, India head of Boeing Defence Integrated, praised the accord as a cornerstone of the increasing trust forged by both countries. The agreement will make it easier to share important US defence technology with India, he said in a statement. Boeing looks forward to working within the framework of this agreement to support India in modernising its defence forces, he said. Richard Kirkland, Lockheed Martins South Asia president, also applauded the deal. We look forward to supporting the requirements of the Indian armed services in partnership with Indian industry, Kirkland told AFP in an email.