By Krittivas Mukherjee

L'AQUILA, Italy, July 10 (Reuters) - Indian Prime Minister Manmohan Singh expressed his concern at Pakistan's lack of progress in investigating those behind the Mumbai attacks in a meeting with U.S. President Barack Obama, an Indian official said on Friday.

Singh also discussed militancy in Pakistan and regional security in a series of bilateral meetings and talks with leaders of Germany, France, Russia and Australia on the sidelines of the G8 summit in Italy late on Thursday, officials said.

Analysts say Singh's move could cast a shadow over a meeting of the Indian and Pakistani foreign secretaries in Egypt next week as the two nuclear-armed neighbours try to reduce tensions that flared after 10 Islamist gunmen killed 166 people in Mumbai.

"Our concern at the lack of progress in investigating the attack was conveyed," said a senior government official who did not want to be identified. "He (Singh) also discussed regional security."

India suspended a peace process, begun in 2004, after the attacks by Islamist militants on its commercial hub, Mumbai, in November.

India blamed the Pakistan-based Lashkar-e-Taiba militant group for the attack and has rejected Pakistan's call to resume the peace process until Islamabad takes further action against the group.

The United States is keen for both countries to resume talks to ease tensions on Pakistan's eastern border with India, so it can focus on fighting Taliban militants on its western border with Afghanistan.

But New Delhi is walking a fine line -- keeping the door open for an eventual resumption of full dialogue without appearing to go soft on its rival with whom it has fought three wars.

Singh and his Pakistani counterpart are also expected to meet in Egypt. (Editing by Sugita Katyal)

AlertNet news is provided by