Speaking from London, Maskhadov's UK-based envoy said the death of the former president of Chechnya was a big loss but would not spell the end of the separatists' effort to break away from Moscow's control.
Akhmed Zakayev, who was Maskhadov's main envoy in the West, said that a successor to the Chechen leader would be named within days.
Maskhadov, 53, was one of Russia's two most wanted men and was killed in an operation by the Russian FSB security service in a village north of the capital, Grozny, officials said.
Putin's enemy dead
The Kremlin, which had accused Maskhadov of masterminding a series of deadly attacks on civilian targets, including last year's Beslan school siege, hailed his death as a success for its policies.
However, most political analysts saw him as the only moderate voice among Chechen guerrillas with whom the Kremlin could negotiate. His death would deal a fatal blow to any chance for peace soon, commentators said.
"Maskhadov will be much more dangerous in death than he could have been even in life"
Zakayev said the killing would very likely trigger revenge attacks.
More dangerous dead
"Aslan Maskhadov will be much more dangerous for the Kremlin leadership in death than he could have been even in life, when he was calling for peaceful dialogue," said Zakayev.
Maskhadov repeatedly had invited Moscow to hold talks with him but the Russian leadership refused, saying it did not negotiate with terrorists.
"Instead of the weak argument that [the Kremlin] has nothing to discuss with Maskhadov ... there is now an overwhelming conclusion: There really isn't anyone to negotiate with anymore," said the Izvestia newspaper.
Hardline Chechen commanders Shamil Basayev and Doku Umarov were the most likely candidates to succeed Maskhadov as head of the self-proclaimed independent Chechnya, said the Russian daily Kommersant.
Tougher position expected
"Both commanders, in contrast to Aslan Maskhadov's declared desire for talks with Moscow, are well-known for their uncompromising and aggressive position towards Moscow," the newspaper said.
Tens of thousands have been
killed on both sides
Maskhadov was elected president of Chechnya during a three-year period in the late 1990s when the region enjoyed de facto independence.
He distanced himself from many attacks Moscow accused him of engineering, instead blaming Basayev for incidents such as the Beslan school siege, in which 330 people - many of them schoolchildren - were killed.
Basayev had also claimed responsibility for the 2002 Moscow theatre siege, which ended bloodily when Russian special forces released poisonous sleeping gas into the auditorium, killing over 170 of the civilians.
Russia has long said a breakaway by Chechnya would trigger secession drives by other regions in its sprawling federation.
In the past decade, Russian troops have fought two wars in Chechnya.
Tens of thousands were killed on both sides in the first conflict from 1994-96, when Maskhadov was commander-in-chief of
In 1999, Putin sent troops back into the territory to burnish his strong-arm image in the run-up to presidential elections in 2000.
Since then, a low-level war has continued with regular losses for Russian troops, Chechen fighters and Chechen civilians caught in the crossfire.