By Tulay Karadeniz and Gabriela Baczynska
ANKARA/MOSCOW (Reuters) - Russian President Vladimir Putin's visit to Turkey on Monday will have trade and energy issues at its heart, but is not expected to bridge deep differences over Syria and Crimea.
The two issues have tested a relationship usually kept on track by mutual economic advantage: Russia is Turkey's main energy supplier, and Ankara is Moscow's second biggest trade partner after Germany.
Turkish President Tayyip Erdogan has strongly criticised Russia's backing for Syrian President Bashar al-Assad. And Turkey has strong links with the Muslim Tatar population of Crimea, which Russia annexed from Ukraine in March.
With Erdogan and Putin set to chair the fifth annual meeting of a council to improve trade and relations, several deals are expected to be signed, officials on both sides said.
State monopoly Rosatom, which is building Turkey's first nuclear plant, expected to be worth $20 billion, will continue pushing for "investor status", which would cut tax on profit to 2 percent from 20, Putin's top foreign policy aide Yuri Ushakov told journalists on Friday.
Turkey's imminent ascension to the presidency of the G20 makes bilateral ties particularly important, Ushakov said, adding that Syria would be discussed in "great detail".
Talks on Turkey's troubled neighbour are unlikely to be more than an exchange of very differing views, according to Hasan Selim Ozertem, an analyst at Ankara-based think tank USAK.
Erdogan has become Assad's most vocal critic and has lambasted the United Nations Security Council, and Russia in particular, for stalling on an international response to the civil war in Syria, which has left nearly 200,000 dead.
"It seems that topics regarding strengthening energy and trade ties are richer this time," Ozertem said.
Whilst Turkey's role in NATO is also likely to strain relations, its interest in building power plants and gas storage facilities could push trade volume to $40 billion from around $32 billion last year, Ozertem said.
The announcement of a revision to natural gas prices, negotiated by Turkish Energy Minister Taner Yildiz during a trip to Moscow earlier this week, may be delayed, a senior Turkish official told Reuters, but talks will continue to boost trade towards a target of $100 billion by 2020.
"Russia is very keen on investing in Turkey," the official said.
(Additional reporting by Orhan Coskun in Ankara; Writing by Ece Toksabay and Jonny Hogg; Editing by Nick Tattersall and Mark Trevelyan)