A total of 166 people died in the attacks in Mumbai in November 2008
India and Pakistan will work together to fight terrorism, the countries' prime ministers have announced.
Meeting in Egypt, they said the fight against their "main threat" should not be linked to wider peace talks.
However, India's Manmohan Singh later said no dialogue would start until those behind last year's attacks in Mumbai (Bombay) were "brought to book".
Relations between the two countries deteriorated after the attacks in which militants killed more than 160 people.
India has accused Pakistan-based fighters from the banned militant group Lashkar-e-Taiba of carrying out the attacks.
Pakistan has admitted they were partly planned on its soil - and vowed to do all it can to bring the suspects to justice.
Jill McGivering, BBC News
Broadly speaking the prime ministers emerged in positive mood. Both sides found agreement on some basic principles.
Crucially, they also agreed to separate their debate about action on terrorism from more general dialogue. That was a key demand from Pakistan - and may make it possible for the mechanism of talks to be revived, independent of India's continuing demands for tougher action on militant groups like Lashkar-e-Taiba, the group India blames for the Mumbai attacks.
That apparent concession from India was offset by some tough statements on terrorism. Mr Singh has to face an Indian public which is still angry about the Mumbai attacks and frustrated that, so far, Pakistan has done little to convict those responsible.
Prime Ministers Yousuf Raza Gilani of Pakistan and Manmohan Singh of India made the pledge after meeting in Egypt.
The talks on Thursday - on the sidelines of the Non-Aligned Movement's summit in Egypt - were the third high-level meeting between the two nuclear-armed neighbours since the Mumbai attacks last November which brought an abrupt halt to peace talks.
"Both leaders affirmed their resolve to fight terrorism and co-operate with each other to this end," the joint statement of the talks said.
"Prime Minister Singh reiterated the need to bring the perpetrators of the Mumbai attacks to justice and Prime Minister Gilani assured that Pakistan will do everything in its power in this regard."
The two prime ministers agreed to co-operate on the investigation.
"Pakistan has provided an updated status dossier on the investigations of the Mumbai attacks," their statement said.
The two leaders also agreed to "share real-time, credible and actionable information on any future terrorist threat".
Last week Pakistan said the trial of five men suspected of involvement in the attack on Mumbai's Taj Hotel was likely to start this week.
In a move likely to please Islamabad, the prime minister's joint statement said action on terrorism "should not be linked to the composite dialogue process" - which includes talks on the disputed territory of Kashmir.
The BBC's Sanjoy Majumder in Delhi says many in India will see this as a major climb-down in Delhi's stance.
And moments after the joint statement had been issued, Mr Singh appeared to contradict the joint statement.
He told a news conference dialogue "cannot begin unless and until terrorist heads which shook Mumbai are properly accounted for, (the) perpetrators of these heinous crimes are brought to book".