MOSCOW, Nov 29 (Reuters) - Russia"s No. 2 bank VTB (VTBR.MM) will remain the controlling shareholder of grains business Demetra for at least another three years and could then consider floating it in an IPO, Chief Executive Andrey Kostin told Reuters. The state-controlled bank became the largest operator of Russia"s grain export infrastructure and a major grains trader after a series of acquisitions in recent years. It said in 2019, it planned to expand its grains business further and then exit. Once the development stage is complete, VTB could consider various options for selling its stake, including an initial public offering of Demetra"s shares, its CEO said. "I think it will take us three years, at least, before we create such a value that we would be interested in selling. Eventually, maybe we will go out through an IPO, but not now - there is still a lot of work to be done," Kostin said in an interview conducted for publication on Monday. VTB"s Demetra holds stakes in several Russian Black Sea grain export terminals and Russia"s largest grain railcar owner Rustranscom. It is also Russia"s third largest wheat exporter, supplying Algeria among other markets. "We have at least three more projects (at Demetra) to expand existing or build new port capacity, to develop other logistics, digital development," Kostin said. The current shareholder structure at Demetra, in which VTB owns a controlling stake and two Russian investors - Agronova and Marathon - share the rest, is stable, and VTB is fine with it, the CEO said. However, a good offer from a foreign fund or a portfolio investor could still be considered, he added. "We once had talk about a possible entry of foreign funds - and that is not a bad thing when you bring a serious foreign investor into a company and then go for an IPO, it can have a positive effect on the share price," Kostin said. "I would be flexible here." "If a good portfolio investor comes along, why not? But this is purely my general thinking, this issue has not been discussed - if suddenly there is a good offer at a good price, we will sit down with partners at the negotiating table and make a decision," he added.